National Climate Report - October 2015


Maps and Graphics

Temperature and Precipitation Ranks

U.S. Percentage Areas

More Information


National Overview:



October Extreme Weather/Climate Events

Supplemental October 2015 Information


 Average Temperature Departures (October)
October Average Temperature Departures
 October Percent of Average Precip
October Percent of Average Precipitation

  • Climate Highlights — October

Temperature

    October 2015 Statewide Temperature Ranks Map

    October 2015 Statewide Precipitation Ranks Map
    October 2015 Statewide Temperature and Precipitation ranks
  • The October contiguous U.S. average temperature was 57.4°F, 3.3°F above the 20th century average. This was the fourth warmest October on record and warmest since 1963.
  • Fourteen states from the Great Plains to West Coast, including Alaska, had an October temperature that was much above average, with numerous locations within those states being record warm. Washington had its warmest October on record with a temperature of 52.8°F, 5.6°F above average, besting the previous record of 52.3°F set in 1988.
  • Near-average October temperatures were observed across the Ohio Valley, Southeast, and Northeast, with below-average temperatures in parts of New England.
  • The October contiguous U.S. maximum (daytime) temperature was 69.3°F, 2.5°F above average, the 15th warmest on record. Above-average maximum temperatures were observed in the West, where seven states across the Rockies and Northwest and Alaska had maximum temperatures that were much above average. Below-average maximum temperatures were observed in the Southeast.
  • The October contiguous U.S. minimum (nighttime) temperature was 45.5°F, 4.0°F above average. This was the second warmest October minimum temperature on record. Only October 1947 had a warmer minimum temperature, at 46.2°F. Much of the country had warmer than average minimum temperatures, with the largest departures from average across the West. Eights states were record warm, while an additional nine states were much warmer than average.
  • Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during October was 32.2 percent below average and the 27th lowest in the 1895-2015 period of record.
  • During October, there were 3,247 record warm daily high (1,055) and low (2,192) temperature records, which is more than three and a half times the 845 record cold daily high (668) and low (177) temperature record.

Precipitation

  • The October precipitation total for the contiguous U.S. was 2.75 inches, 0.59 inch above average and the 20th wettest on record.
  • Above-average precipitation was observed across the southern half of the contiguous U.S. from the Southwest, through the Southern Plains, and into the Southeast. Seven states had October precipitation totals that were much above average. South Carolina had at least* its second wettest October with 10.36 inches of precipitation, 7.37 inches above average. The state observed 11.56 inches of precipitation in October 1990.
    • *Please note that several single-day rainfall totals in South Carolina, and in Texas (see below) were so large that they initially were flagged as invalid by NCEI's automated quality control algorithms. It is very likely that, upon review, the October averages for these states will increase. NCEI will provide an update when this review is complete later in November.
  • Below-average October precipitation was recorded in parts of the Northwest, Ohio Valley, and Florida.
  • According to the November 3rd U.S. Drought Monitor report, 26.2 percent of the contiguous U.S. was in drought, down about 5.2 percent compared to September 29th. Drought conditions dramatically improved across parts of the Southern Plains and Lower Mississippi River Valley where heavy precipitation flooded the region in late October. Drought also improved across the Southeast and in parts of the Northwest. Drought conditions worsened across parts of the Central Plains and Midwest. Precipitation was spotty across the West with long-term drought conditions continuing to plague the region.

Significant Events

  • In early October, a strong low pressure system moved into the Southeast as Hurricane Joaquin moved off the East Coast. The two systems interacted, streaming deep tropical moisture into the Carolinas over a five-day period. Historic rainfall totals of 15-20 inches were widespread with localized totals greater than 25 inches around Charleston, South Carolina. The heavy rainfall caused significant flooding across the region, including coastal flooding that was exacerbated by strong onshore flow and astronomical high tides. The flooding resulted in over 400 roads, including Interstate Highways, being closed and at least 16 fatalities.
  • In late October, several storm systems impacted the Southern Plains and Lower Mississippi River Valley, including the remnants of Hurricane Patricia. Heavy rainfall caused significant flooding across the region. On October 30th, Austin, Texas's Bergstrom Airport was forced to close when 5.76 inches of rainfall was observed in one hour, adding to the calendar-day total of 14.99 inches. This was the second wettest day on record for the city. Texas as a whole had its fifth wettest October with 5.84 inches of precipitation, 3.31 inches above the 20th century average.

  • Climate Highlights — year-to-date (January–October)

Temperature

Precipitation

Extremes

  • The U.S. Climate Extremes Index (USCEI) for the year-to-date was 40 percent above average and the 13th highest value on record. On the national scale, extremes in warm maximum and minimum temperatures, one-day precipitation totals, and days with precipitation were much above average. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, land-falling tropical cyclones, and drought across the contiguous United States
    • Regionally, the CEI was record high in the West and Northwest. In the West, the components that examine extremes in warm daytime and nighttime temperatures, the spatial extent of drought, and days without precipitation were much above average. In the Northwest, extremes in warm daytime and nighttime temperatures, the spatial extent of drought, and one-day precipitation totals were above average. The Southwest had its sixth highest year-to-date CEI due to extremes in warm daytime and nighttime temperatures and days with precipitation.

**A comparison of the national temperature departure from average as calculated by NCDC's operational dataset (nClimDiv), the U.S. Historical Climatology Network (USHCN), and the U.S. Climate Reference Network (USCRN) is available on our National Temperature Index page.**



Regional Highlights:

These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.

  • Northeast Region: (Information provided by the Northeast Regional Climate Center)
  • The Northeast experienced near-normal temperatures in October. The region's average temperature of 49.1 degrees F (9.5 degrees C) was only 0.3 degrees F (0.2 degrees C) below normal. Nine of the region's twelve states were within 0.5 degrees F (0.3 degrees C) of normal. Overall, temperatures ranged from 1.3 degrees F (0.7 degrees C) below normal in Maine to 0.5 degrees F (0.3 degrees C) above normal in West Virginia.
  • Precipitation was also near normal in October. The region picked up 3.62 inches (91.95 mm), which was 93 percent of normal. Precipitation in seven states was within 10 percent of normal, while five states were more than 10 percent drier than normal. For all states, precipitation ranged from 65 percent of normal in Connecticut to 109 percent of normal in Pennsylvania.
  • At the start of October, 49 percent of the Northeast was abnormally dry, with another 9 percent of the region experiencing moderate drought. Conditions improved through mid-month, but remained steady for the rest of the month. In the October 29 U.S. Drought Monitor, 21 percent of the Northeast was abnormally dry and 6 percent of the region was experiencing moderate drought.
  • Several consecutive days of strong onshore winds, large waves, and elevated tides in early October caused significant beach erosion and moderate coastal flooding in parts of the mid-Atlantic. Winds gusted to 62 mph (28 m/s), and preliminary data showed wave heights of up to 11 feet (3.4 m) near the New Jersey and Delaware coasts, with waves of up to 20 feet (6 m) further offshore. After the storm, some beaches were less than half their original size, while some beaches' dunes became cliffs up to 15 feet (4.6 m) high. Tidal flooding caused numerous road closures and sent water into buildings and homes. In addition, up to 5 inches (127 mm) of rain fell. Another storm in late October also brought gusty winds and heavy rain to the Northeast. Sustained winds of 40 mph (18 m/s) and gusts to 69 mph (31 m/s) led to downed trees and scattered power outages. Up to 4 inches (102 mm) of rain fell, causing minor flooding.
  • For more information, please go to the Northeast Regional Climate Center Home Page.
  • Midwest Region: (Information provided by the Midwest Regional Climate Center)
  • October temperatures in the Midwest were slightly above normal. Temperatures averaged below 50 degrees F (10 C) in the northern quarter of the region and warmed to about 60 degrees F (16 C) along the southern border of Missouri. The warmest area was 2 to 4 degrees F (1 to 2 C) above normal in northwest Iowa and western Minnesota. The rest of the region was just above normal. The second week of the month was well above normal across the region with many highs above 90 degrees F (32 C) as far north as northern Minnesota on 11th. Statewide temperature in Minnesota ranked as the 17th warmest on record (1895-2015) for the month with the other states all ranking among their 30 warmest over the same period.
  • Large parts of the Midwest were very dry in October. Rainfall totals were less than 50 percent of normal from southwest Iowa, through most of Missouri and Illinois, and into southeast Wisconsin, northwest Indiana, and southwest Michigan. The driest area was along the Mississippi River south of St. Louis with totals less than 25 percent of normal. Above normal precipitation was limited to two areas, east central Minnesota into western Wisconsin and the southeast, where totals were 100 to 150 percent of normal. The first snows of the season for the region came to northern Wisconsin and Michigan mid-month (16th to 18th) with measurements up to 6 inches (15 cm) recorded. Moisture from hurricane Patricia, which had come ashore in western Mexico, moved into the region on the 27th and 28th bringing widespread rains, with particularly heavy rains in the lower Ohio River Valley. The above normal rainfall totals in this area were largely due to this event. Missouri had the driest September-October period since 1963 statewide with some locations in the state setting record lows for October or September-October.
  • Drought expanded in the region due to the dry conditions. As of the September 29th US Drought Monitor, only three Midwest states had small areas of drought, covering just 1 percent of the region. By the October 27th version, just before the rains from Patricia, drought had expanded to every Midwest state except Ohio and covered 16 percent of the region. Abnormally dry conditions also expanded from 20 to 49 percent of the region in the same period.
  • The first freeze had come to the upper Midwest in September, but widespread freezes occurred in the second half of October to nearly the entire region. Some locations in Missouri and Kentucky had yet to have a freeze at the end of October.
  • Severe weather was only reported on three days in the month with just a handful of reports each day. Severe winds were reported in Kentucky on the 9th, severe wind and hail in Michigan on the 15th, and 6 EF-0 tornadoes in northwest Iowa on the evening of the 23rd. Tornado damage was mostly limited to agricultural areas but the last tornado also damaged the roof of a home near Larrabee, Iowa.
  • Harvest was nearing an end for corn and soybeans across the Midwest as October came to a close. All nine states were at or ahead of their 5-year averages, with many exceeding 90 percent of the crop harvested. Yields were particularly good in the northern parts of the region. Further south yields were lowered due to wet periods earlier in the growing season.
  • For details on the weather and climate events of the Midwest, see the weekly summaries in the Midwest Climate Watch page.
  • Southeast Region: (Information provided by the Southeast Regional Climate Center)
  • Temperatures were near average across much of the Southeast region, with very few extremes recorded during October. Mean temperatures were 1 to 2 degrees F (0.6 to 1.1 degrees C) above average across Alabama and the Florida Peninsula. Within this area, Vero Beach, FL (1943-2015) observed its fifth warmest October mean temperature on record. Mean temperatures were well above average in Puerto Rico and the U.S. Virgin Islands. Three reporting stations in Puerto Rico, including San Juan (1899-2015), Guayama (1914-2015), and Juncos (1931-2015), observed their warmest October mean temperatures on record. In addition, a 21-day streak of 90 degree F (32.2 degrees C) or greater days at San Juan, PR ended on the 15th of the month, which ranks as the tenth longest streak on record for this location. The warmest weather of the month occurred from the 7th through the 9th. During this three-day period, maximum temperatures were at least 80 degrees F (26.7 degrees C) across the entire region south of Virginia, with a few locations in southern Florida and northern Alabama reaching the lower 90s F (32.8 to 33.9 degrees C). In contrast, the coolest weather of the month occurred from the 19th through the 20th, as a strong Canadian high pressure system settled over the region. Daily minimum temperatures fell into the lower 30s F (-0.6 to 0.6 degrees C) across much of the Carolinas and Virginia, resulting in the first frost of the season.
  • Precipitation was highly variable across the Southeast region during October. The driest locations were found across much of Florida and southern Georgia, where monthly precipitation totals were between 5 and 50 percent of normal. West Palm Beach, FL (1888-2015) and Key West, FL (1871-2015) observed their second driest October on record with only 0.91 (23 mm) and 0.75 inch (19 mm) of precipitation, respectively. Precipitation was highly variable across Puerto Rico and the U.S. Virgin Islands. While San Juan, PR observed its fifth driest October on record with only 1.77 inches (45 mm) of precipitation, Aibonito, PR (located about 25 miles southwest of San Juan) recorded 13.92 inches (354 mm) of precipitation during the month. In contrast, the wettest locations were found across southern Alabama, northern Georgia, the Carolinas, and southwestern Virginia, where monthly precipitation totals were 2 to as much as 15 inches (51 to 381 mm) above normal. A streak of 12 consecutive days with measurable precipitation at Raleigh, NC (1887-2015) ended on October 5th, tying the longest streak on record for this location. Columbia, SC (1887-2015), Charleston, SC (1938-2015), and Florence, SC (1948-2015) observed their wettest October on record with 14.46 (367 mm), 18.91 (480 mm), and 12.81 inches (325 mm) of precipitation, respectively. October 2015 was also the second wettest month all time for Charleston and the sixth wettest month on record for Columbia. Much of this precipitation fell during a historic rainfall event across South Carolina and coastal North Carolina between October 1st and 5th, which produced destructive flooding in these cities as well as the surrounding rural areas. On the 3rd, Charleston recorded its all-time greatest 1-day rainfall with 11.50 inches (292 mm) of precipitation, and Columbia observed its wettest day on record with 6.87 inches (174 mm) of precipitation on the 4th. During this 5-day event, the greatest CoCoRaHS rainfall total in the Charleston area (and all of South Carolina) was 26.92 inches (684 mm), recorded at the Mt. Pleasant 6.4 NE station. Similarly, the Gills Creek RCWINDS (Richland County Emergency Services Department) Mesonet station observed the greatest 5-day rainfall total in the Columbia area, with 21.5 inches (546 mm) of precipitation.
  • There were only 9 severe weather reports across the Southeast during October, which is about 15 percent of the median monthly frequency of 58 reports during the 2000-2014 period. All but one of these reports were for damaging thunderstorm winds. At least one severe weather report was recorded within the region on only 5 days during the month. On the 1st, strong thunderstorm winds caused two trees to fall onto multiple residences in Houston County, GA. Only one tornado was confirmed across the Southeast during the month, which is well below the short-term (2000-2014) median frequency of 10 tornadoes observed during October. On the 11th, a waterspout came ashore on the southern side of the Sunshine Skyway Bridge near St. Petersburg, FL. This EF-0 tornado significantly damaged a U.S. Postal Service 18-wheeler truck as it crossed the bridge, but the driver was not injured.
  • Drought conditions improved significantly across much of the Southeast region during October. The percentage of the region under drought-free conditions (less than D1) increased from 88 percent on September 29th to 94 percent on October 27th. Following the historic rainfall during the first week of the month, moderate-to-severe (D1 and D2) drought conditions were completely ameliorated across the Carolinas. Moderate drought conditions were eliminated over southern Alabama in the vicinity of Mobile; however, a new area of moderate drought developed over west-central Alabama in response to below-normal precipitation. Beneficial rainfall over eastern Puerto Rico resulted in a 12 percent decrease of severe-to-extreme (D2 and D3) drought coverage by the end of the month. Seasonal yields for several fields crops, including cotton, peanuts, and soybeans, were substantially reduced across the Carolinas due to excessive rainfall during early October. The first frost of the season in mid-October damaged portions of the tobacco harvest in southern Virginia and North Carolina. In fact, nearly 600 barns filled with curing tobacco leaves were lost in Rockingham County, NC.
  • For more information, please go to the Southeast Regional Climate Center Home Page.
  • High Plains Region: (Information provided by the High Plains Regional Climate Center )
  • A running theme this year has been the warmth, especially in the western and central portions of the country. This month was no exception with the majority of the U.S. experiencing temperatures that were well above normal. The largest temperature departures occurred across portions of the Plains and the West where temperature departures ranged from 4.0-8.0 degrees F (2.2-4.4 degrees C) above normal. Some isolated areas of Oregon, Idaho, and Wyoming topped that range, coming in above 8.0 degrees F (4.4 degrees C) above normal. Other areas of the U.S., such as the East Coast, were within 2.0 degrees F (1.1 degrees C) of normal. Two notable precipitation events occurred this month due to tropical systems. At the beginning of the month, a low pressure system pulled in tropical moisture from Hurricane Joaquin and brought devastating flooding to South Carolina when it dumped anywhere from 12.00-24.00 inches (305-610 mm) of rain on the state. It is important to note that although Hurricane Joaquin never made landfall in the U.S., its moisture contributed to the historic flooding. At the end of the month, the remnants of Hurricane Patricia, which was the strongest tropical cyclone to ever be recorded in the Western Hemisphere, brought torrential rains to Texas and Louisiana. Strong systems also brought above normal precipitation to the Four Corners states and portions of California and Nevada. A few areas of the country were on the dry side, including central and northern California, parts of the central U.S., and Florida. Here in the High Plains region, the combination of warm and dry conditions in the eastern part of the region has had varied impacts. On one hand, the warm weather generally allowed for a later first frost than usual, which extended the growing season for garden vegetables such as tomatoes and peppers. But, ongoing dry conditions in Kansas have already impacted winter wheat. According to Kansas State extension, the dryness in central Kansas has been problematic for winter wheat emergence. Producers may need to replant in these areas of uneven and poor emergence.
  • Warm weather continued this month for the High Plains region with average temperatures generally in excess of 4.0 degrees F (2.2 degrees C) above normal for a second month in a row. The largest departures occurred across portions of southern and central Wyoming and pockets of Colorado, South Dakota, and North Dakota where average temperatures were 6.0-8.0 degrees F (3.3-4.4 degrees C) above normal. With these departures, it is no surprise that many locations ranked in the top 10 warmest Octobers on record. A few examples include McCook, NE (warmest), Cheyenne, WY (3rd), and Denver, CO (6th). The 11th was a particularly hot day for the region, with temperatures soaring above 90 degrees F (32.2 degrees C). Many locations tied or set new records for highest October temperature on record that day. Two impressive records occurred in Fargo, North Dakota, which had a high temperature of 97 degrees F (36.1 degrees C) and Norfolk, Nebraska, which had a high temperature of 98 degrees F (36.7 degrees C). With data going back to 1881, Fargo beat its previous record set on October 5, 1963 by 4 degrees F (2.2 degrees C)! Because this fall has been so warm, many people have wondered if there have been any new records for latest first fall frost. Except for the mountainous areas, the average date of the first fall frost (32 degrees F/0 degrees C) ranges from mid to late September in northern areas and mid to late October for southern areas. A look at this fall's minimum temperatures shows that many locations in the region had a later than average first fall frost, but it was not a record-breaking year. A few isolated areas, such as Bismarck, North Dakota, had early freezes, while Omaha, Nebraska has yet to have a freeze.
  • Precipitation varied across the High Plains region this month, with some locations receiving little to no precipitation and others receiving greater than 150 percent of normal precipitation. Dry areas included eastern Kansas, eastern Nebraska, north-central South Dakota, east-central North Dakota, and a swath running from the southwest to the northeast through central Wyoming. These areas received, at most, 50 percent of normal precipitation. In some of these areas, the dryness was not isolated to October and drought conditions emerged. Meanwhile, much of Colorado, southwestern Kansas, the panhandle of Nebraska, western portions of the Dakotas, and southeastern and northwestern Wyoming received at least 150 percent of normal precipitation. The largest departures occurred in southwestern Kansas where some locations received surpluses of up to 3.00 inches (76 mm). Because of the varied precipitation, there were extremes on both ends of the spectrum. Kansas, Nebraska, and Wyoming all had large areas that received either less than 50 percent of normal precipitation or greater than 150 percent of normal precipitation. Take Wyoming for example. With records going back to 1948, Laramie had its 5th wettest October on record with 2.05 inches (52 mm). This amount was 1.25 inches (32 mm) above normal, or 256 percent of normal. Meanwhile, Rock Springs had its 9th driest October with only 0.15 inches (4 mm), or 17 percent of normal precipitation (period of record 1948-2015). Every fall in the High Plains region, we start to turn our attention to snow, but with the exceptionally warm weather this season, snow may not be on everyone's minds just yet. Some areas of Colorado and Wyoming have received no snowfall yet this season and are already at least two weeks past their average first snowfall date. For instance, Boulder, Colorado's average first snowfall is October 18th, but they have yet to receive any snow this season. In fact, the temperature dipped below freezing only one morning all month long. On average, Boulder receives 5.6 inches (14 cm) of snow in October (period of record 1893-2015). Cheyenne, Wyoming only picked up a Trace of snowfall this October, although the normal for the month is 5.0 inches (13 cm). With snow in the forecast for the first week of November, this would put 2015 as one of the top 10 latest first snowfalls on record for Cheyenne (period of record 1883-2015).
  • A continuation of dry conditions in the eastern part of the High Plains region has led to changes in the U.S. Drought Monitor over the past month. The total area in drought (D1-D4) in the region increased from just under one percent to about 4 percent. Moderate drought conditions (D1) developed in portions of central and eastern North Dakota, eastern Kansas, and far southeastern Nebraska. Over the past three months, these areas have received less than 50 percent of normal precipitation. This has translated into deficits of 2.00-6.00 inches (51-152 mm) to the north and 4.00-8.00 inches (102-203 mm) in the south. The area of D1 that emerged in north-central Kansas last month expanded slightly on the southern end and improved to abnormally dry conditions (D0) in the middle, dividing the area into two. By the end of the month, the total area in drought in Kansas had increased to just over 14 percent. D0 also expanded this month and now encompasses over 40 percent of the region. When D0 develops, it highlights areas that should be monitored for possible drought development. Areas with D0 expansion included central and eastern Kansas, northwestern Colorado, southwestern Wyoming, southern Nebraska, northern South Dakota, and eastern North Dakota.
  • For more information, please go to the High Plains Regional Climate Center Home Page.
  • Southern Region: (Information provided by the Southern Regional Climate Center)
  • A continuation of dry conditions in the eastern part of the High Plains region has led to changes in the U.S. Drought Monitor over the past month. The total area in drought (D1-D4) in the region increased from just under one percent to about 4 percent. Moderate drought conditions (D1) developed in portions of central and eastern North Dakota, eastern Kansas, and far southeastern Nebraska. Over the past three months, these areas have received less than 50 percent of normal precipitation. This has translated into deficits of 2.00-6.00 inches (51-152 mm) to the north and 4.00-8.00 inches (102-203 mm) in the south. The area of D1 that emerged in north-central Kansas last month expanded slightly on the southern end and improved to abnormally dry conditions (D0) in the middle, dividing the area into two. By the end of the month, the total area in drought in Kansas had increased to just over 14 percent. D0 also expanded this month and now encompasses over 40 percent of the region. When D0 develops, it highlights areas that should be monitored for possible drought development. Areas with D0 expansion included central and eastern Kansas, northwestern Colorado, southwestern Wyoming, southern Nebraska, northern South Dakota, and eastern North Dakota.
  • October precipitation in the Southern Region varied spatially from extremely wet to extremely dry. Though all six states in the region experienced a wetter than normal month, conditions in northern Arkansas and central/eastern Oklahoma were quite dry with most station reporting less than 70 percent of normal rainfall. In the northern counties of Arkansas and Oklahoma, many stations reported less than half the monthly expected precipitation. Elsewhere in the region, conditions were very wet. A slow moving cold front, combined with the remnants of Hurricane Patricia dropped more than 10 inches (254 mm) of rain across areas of southern Texas and southeastern Louisiana. The state-wide precipitation totals for the month are as follows: Arkansas reporting 3.66 inches (92.96 mm), Louisiana reporting 7.56 inches (192.02 mm), Mississippi reporting 5.35 inches (135.89 mm), Oklahoma reporting 3.11 inches (78.99 mm), Tennessee reporting 3.84 inches (97.54 mm), and Texas reporting 5.84 inches (148.34 mm). For Texas, it was their fifth wettest October on record. Louisiana experienced its twelfth wettest October and Mississippi its fourteenth wettest. All other state rankings fell within the two middle quartiles. All state records are based on the period spanning 1895-2015.
  • Heavy precipitation near the end of the month helped alleviate drought conditions across the Southern Region. As of November 3, 2015, only 7.15 percent of the Southern Region is classified in moderate drought. All severe drought and beyond has been removed.
  • The passage of a cold front on October 24-25 dumped record rainfalls across the southern parishes of Louisiana. Local flooding was reported in several parishes. One day totals over over 8 inches (203.2 mm) were common, and in New Orleans, approximately 22,000 people were left without power. One week later, an additional 4-5 inches (101.6-127.0 mm) fell across southern Louisiana causing local flooding in Baton Rouge.
  • In Texas, unseasonable temperatures and worsening drought conditions were common for the first half of the month. Over the last two weeks rainfall across the state has broken records and brought with it dangerous flash flooding and severe weather. Burn bans are now ineffect for 143 counties across the state. Over 5000 acres were burned by a wildfire in Bastrop County in addition to over 70 homes. A change in weather pattern brought higher humidity values and eventually rain, which helped firefighters contain the fire. Ensuing rainfall at the end of the month helped eliminate the developing flash drought conditions and brought some hydrological improvement as well, as reservoirs had dropped 4% this month, a time when levels usually don't change, before improving by 6%. Although the changing weather pattern helped the fire and drought conditions, it did not arrive without its own destruction. Areas of the state such as Corsicana, southern Austin, and northern Houston received upwards of 20 inches (508 mm) of rain throughout the month, with most of the rain falling in a period of two weeks. The Dallas/Fort Worth area also saw heavy rains totaling over 12 inches (304.8 mm). Emergency officials responded to over 1000 weather related incidents such as high-water rescues, stranded motorists, etc, across several cities during the heavy rainfall period. Stretches of highways needed to be shut down causing traffic headaches for weekend travelers and local commuters. Late-month storms brought further flooding from high rivers and tornadoes, the later destroying 70 homes in La Porte. Damages due to the two record flooding events thus far could reach $3 billion. In an effort to better predict and understand tornado formation, Texas will see $1.9 million of a $5.7 million research agreement towards hazardous weather research. (Information provided by the Texas Office of State Climatology).
  • For more information, please go to the Southern Regional Climate Center Home Page.
  • Western Region: (Information provided by the Western Region Climate Center)
  • Temperatures were well above normal throughout the West this month. Widespread areas had temperatures 4-6 F (2-3 C) above normal, with even greater departures across the Intermountain West and coastal California. Precipitation was above normal in much of the Great Basin and Southwest, while coastal areas generally saw below normal rainfall.
  • An "inside slider" low-pressure system brought precipitation to the Northwest, Great Basin, Sierra Nevada, and the Southwest over the first week of October. The low then cut off from the large-scale flow, traversed southwest across Mexico, and returned to southern California on October 15-16, bringing moist air and another round of precipitation. During this and two other storm systems, Las Vegas, Nevada recorded 1.16 in (29 mm) of rain for its 3rd wettest October 1958-present. Northwest of Las Vegas, Pahrump, Nevada observed 2.48 in (63 mm) rainfall for the month, 958% of normal, their wettest October since consistent records began in 1959. Death Valley, California picked up 1.14 in (29 mm) for the month, its wettest October on record, 1628% of normal and roughly half of their typical annual precipitation. Rome, Oregon reported 2.08 in (53 mm) of rain, 346% of normal, the 5th wettest October in the station's 66-year record. In southeastern New Mexico, Roswell received 4.63 in (118 mm) for the month, 346% of normal. Flagstaff, Arizona received 224% of normal October precipitation (3.72 in/94 mm). To the north, in Northeastern Montana, Glasgow received 1.67 in (42 mm) this month. This was the 4th wettest October in Glasgow's 67-year record.
  • Many coastal locations remained dry or saw below average precipitation, not uncommon in this transition to the wet season. San Francisco, California saw no precipitation this month, which occurred in 12 other years in the station's 167-year record. Drought conditions held steady for California this month and improvements were seen in Arizona, New Mexico, the southern portions of Utah and Idaho, northern Montana, and northwest Washington, generally in association with October's areas of above normal rainfall. Small areas of deteriorating drought conditions were observed along the western Colorado-Wyoming border, where precipitation was 50% of normal or less this month.
  • Temperatures were exceptionally warm throughout the West this month. Though a few low-pressure systems traversed the area, anomalously strong high pressure dominated in between storm events. In southern California, many coastal locations from Monterey Bay to San Diego had a record warm October, likely in association with the anomalously very warm coastal waters. Temperatures at Santa Barbara averaged to 70.5 F (21.4 C), 8.9 F (4.9 C) above normal and 4 F (2 C) above the previous record set in October 1976 for the warmest in a 75-year record. In San Diego, the average October temperature was 74.4 F (23.5 C), 7.7 F (4.3 C) above normal and 2.2 F (1.2 C) above the previous record set in 1983. Records for San Diego began in 1939. To the north, temperatures at Boise, Idaho averaged to 59.7 F (15.3 C), beating out October 2014 for the second warmest on record and just shy of the 1988 record of 59.8 F (15.4 C). Boise saw its latest 90 F (32.2 C) reading on October 10; the previous record was October 3, 1963; records there began in 1940. Further east, in southeastern Wyoming, Rawlins reported an average 50.8 F (10.4 C) for the month, 7.5 F (4.2 C) above normal, the warmest October in a 65-year record.
  • Precipitation was highly variable across Alaska, with stations along the North Slope observing below normal precipitation and stations in the Interior and Southcentral regions ranging from <50% of normal to >150% of normal. In the Southeast, remnants of Tropical Storm Oho were entrained into a low-pressure system tracking towards Alaska, bringing copious rainfall to Ketchikan on October 7-9. On the 8th, 7.21 in (183 mm) of precipitation was observed, the 6th wettest day since records at Ketchikan began in 1910. Ketchikan recorded 30.64 in (778 mm) for the month, 159% of normal. Above normal temperatures were observed throughout Alaska, with the greatest departures in the Interior, Western, and Southcentral regions. King Salmon reported an average 42.8 F (6 C) for the month, 9.3 F (5.2 C) above normal and the 3rd warmest October since records began in 1917. To the southwest, above normal temperatures continued for some areas of Hawaii. Hilo recorded its warmest October on record at and average 78.7 F (25.9 C) for the month, 3.1 F (1.7 C) above normal. This makes October 2015 the 5th warmest month of all time at Hilo. September, August, and July 2015 hold the 1st, 2nd, and 4th place spots. Precipitation was variable across the state, with Lihue, Kauai in the far northwest observing its 2nd driest October on record at 0.36 in (9 mm), 9% of normal. Hilo, in the southeast, had its 6th wettest October on record with 15.84 in (402 mm), 162% of normal. Records for Lihue began in 1950 and records for Hilo in 1949.
  • October 5th, 18th: Flooding in southern Nevada: Heavy precipitation caused localized flooding in downtown Las Vegas on the 5th. Later in the month, another storm brought high precipitation rates resulting in closure of a portion on Interstate 95, a major route between Reno and Las Vegas. Flooding in this area is more typical of the June-September monsoon season.
  • October 15: Debris-laden flooding on Interstate 5 (Grapevine), California Highway 58 in southern California: Rain rates over 2 inches per hour were observed in association with a low-pressure system. Rain fell on steep areas of the Tehachapi and San Emigdio mountains where it was channeled by terrain and collected debris. The water and debris then inundated the steep alluvial fans and roadways in the area.
  • October 15: California's Folsom Lake reaches lowest level in 20+ years: This major reservoir was at just 17% of capacity and 31% of average level this month, the lowest since the 1987-1992 drought. The record low occurred in 1977.
  • For more information, please go to the Western Regional Climate Center Home Page.

Citing This Report

NOAA National Centers for Environmental Information, State of the Climate: National Climate Report for October 2015, published online November 2015, retrieved on September 21, 2018 from https://www.ncdc.noaa.gov/sotc/national/201510.

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