National Overview - October 2011


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Temperature and Precipitation Ranks
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National Overview:



October Extreme Weather/Climate Events
  • Climate Highlights — October
  • During October, a persistent upper-level weather pattern brought below-normal temperatures to the southeastern United States and above-normal temperatures from the Southwest, across the northern tier of the United States, and into parts of the Northeast. Near-normal precipitation during October across the Southern Plains made little change in long-term drought conditions.
  • The average U.S. temperature in October was 55.7 degrees F, 0.9 degrees F above the 1901-2000 long term average. Precipitation, averaged across the nation, was 2.04 inches. This was 0.07 inch below the long-term average, with variability between regions. This monthly analysis is based on records dating back to 1895.
  • The Southwest, states along the U.S.-Canadian border, and much of the Northeast experienced above-normal temperatures. Eighteen states in total had October temperatures above their long-term averages.
  • Eleven states from Louisiana to West Virginia had October temperatures below their long-term averages. Meanwhile, states in the Pacific Northwest, the Central and Southern Plains, and parts of the Midwest had October temperatures near average.
  • An early season storm brought heavy snow accumulations to the northeastern United States on October 29th–31st. Several locations broke October snow storm records, including New York City’s Central Park, where 2.9 inches of snow accumulated. The highest snowfall amounts were further inland, with over 30 inches accumulating in western Massachusetts and southern New Hampshire. The heavy, wet snow falling on the autumn foliage, combined with strong winds, caused havoc across the region and over 3 million people lost power. The storm received a preliminary rank of Category 1 on the Northeast Snowfall Impact Scale (NESIS), which takes into account snowfall accumulation in populated areas, the only ranking storm on record to occur during October.
  • Several storms impacted the interior western states during October, bringing above-normal precipitation totals to Idaho, Montana, Nebraska, Nevada, and Wyoming. Storms also impacted the eastern seaboard, causing wetter-than-normal conditions in Florida and the Northeast.
  • A string of states from Minnesota, southward along the Mississippi River, to Louisiana observed below-normal precipitation. Eight states were drier than normal during October, with Iowa, Louisiana, and Missouri each having their ninth driest October on record.
  • Dry and warm weather conditions the first few weeks of October created ideal wildfire conditions across the Great Basin and Pacific Northwest, contributing to record acreage burned during the month. Over half a million acres burned nationwide during October — more than double the long-term average.
  • As of November 1st, about nine percent of the contiguous United States remained in the worst category of drought, called D4 or exceptional drought. The footprint was smaller than the nearly 12 percent of the country experiencing exceptional drought at the beginning of October. Slight improvement of drought conditions occurred across the Southern Plains during October, where near-normal precipitation was observed. The drought stricken areas of the Southern Plains would need at least 18 inches of rain in a single month to end the on-going drought.
  • A list of select October temperature and precipitation records can be found here.
  • Climate Highlights — August-October (3-month period) and Year-to-Date period
  • During the August-October period, the United States, as a whole, experienced much-above-normal temperatures with the nationally averaged temperature of 66.0 degrees F ranking as the 10th warmest August-October on record.
  • This same three month period brought very warm temperatures to the western half of the country, where 10 states experienced temperatures among their 10 warmest for the period, including Texas, which was record warm. The Northeast was also particularly warm, where eight states had a top 10 warm August-October. Below-normal temperatures were present for parts of the Ohio Valley and Gulf Coast.
  • Precipitation was a mixed bag during the August-October period, with record wet conditions across the Northeast, and much drier than normal conditions across the central United States. Maryland, New Jersey, New York, Pennsylvania, and Vermont had a record wet August-October period, and seven other states in the region had precipitation totals among their 10 wettest.
  • For the first 10 months of 2011, the contiguous United States was warmer than average. Above-normal temperatures were present across the southern tier of the country and along the eastern seaboard. Texas was record warm for the 10 month period, while Delaware, Maryland, New Jersey, New Mexico, and Oklahoma had temperatures ranking in their top 10 warmest.
  • As a whole, the year-to-date period brought near-normal precipitation to the United States, but there was significant regional variability. States across the Northeast were record wet, including Connecticut, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, and Vermont. Drier than normal conditions prevailed across the southern tier of the country, with record dry conditions reported for Texas.
  • The Regional Climate Extremes Index (RCEI), which is sensitive to extremes in temperature, rainfall, dry streaks, drought, and tropical cyclones, indicated that for the Northeast climate region an area over three times the average value was affected by extreme climate conditions for the year-to-date period. For the South Climate Region, the RCEI was more than twice the average value. The values both represented the second highest values for the January-October period, regionally. For the Northeast, contributing factors included warm minimum temperatures, wet Palmer Drought Severity Index (PDSI), days with precipitation and 1-day precipitation totals. For the South, warm maximum temperatures and dry PDSI values contributed to the high RCEI value.

Alaska Temperature and Precipitation:

  • Alaska had its 31st warmest October on record, with a temperature 2.38°F (1.32°C) above the 1971–2000 average.
  • Alaska had its 33rd warmest August-October on record, with a temperature 0.84°F (0.47°C) below the 1971–2000 average.
  • Alaska had its 36th warmest year-to-date period on record, with a temperature 0.29°F (0.16°C) above the 1971–2000 average.
  • Alaska had its 5th driest October since records began in 1918, with an anomaly that was 33.2 percent below the 1971–2000 average.
  • Alaska had its 38th wettest August-October on record, with an anomaly that was 4.8 percent above the 1971–2000 average.
  • Alaska had its 33rd driest year-to-date period on record, with an anomaly that was 1.3 percent below the 1971–2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below. For information on local temperature and precipitation records during the month, please visit NCDC's Records page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards 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 averaged warmer than normal for the 7th consecutive month. October’s average was 50.7 degrees F (10.4 degrees C), which was 1.3 degrees F (0.61 degrees C) above normal and 0.4 degrees F (0.22 degrees C) warmer than October 2010. It was the warmest October since 2007. Unlike the previous three months, not all the states were warmer than normal. Maryland and West Virginia had temperatures that averaged -0.8 degrees F (-0.44 degrees C) and -1.2 degrees F (-0.67 degrees C), respectively. Departures among the other ten states in the region ranged from +0.4 degrees F (+0.22 degrees C) in Pennsylvania to +3.5 degrees F (+1.94 degrees C) in Maine. It is interesting to note that Vermont had its 19th warmest October in 117 years while West Virginia saw its 35th coolest October since 1895.
  • After a wet August and September, the Northeast began to dry out when high pressure settled over the region around the 5th of October. A string of lovely fall days around the Columbus Day holiday weekend brought tourists back to flood-ravaged areas in New England for fall foliage viewing on the traditional leaf peeping weekend. Unsettled weather returned, with a series of rain events and even a major snowstorm during the second half of October. The end result was above normal precipitation in the Northeast for the third month in a row. The region’s average of 4.83 inches (122.7 mm) was 126 percent of normal. It was the 20th wettest October since 1895. Delaware was the only state with below normal precipitation, at 85 percent of normal. The rest of the states saw departures that ranged from 104 percent of normal in Vermont to 166 percent of normal in Rhode Island. It was the 8th wettest October since 1895 in Massachusetts and the 10th wettest in New Hampshire and Rhode Island. October was the 7th month since January with wetter than normal precipitation the year-to-date total was 47.71 inches (1212 mm). This was 2.19 inches (55.6 mm) more than the region’s annual average and just 6.87 inches (174.5 mm) less than the wettest complete year on record, 1996. If the Northeast tallies average precipitation totals for the next two months, 2011 will be the wettest year since 1895.
  • For the third time in three months, a major weather event impacted the Northeast region. After enduring a hurricane in August, and the remnants of a tropical storm in September, residents in parts of the Northeast had to deal with up to 30 inches (76.2 cm) of heavy, wet snow on October 29th and 30th. Trees still in leaf and even conifers succumbed to the weight of the snow, causing more tree damage and power outages than Hurricane Irene did in August. About 3 million customers, from the central Appalachians of West Virginia to southern Maine, lost power. Some still were in the dark a week later due to the complexity of the restoration effort and the areal coverage of the outages. Tree and branch removal by state and local authorities had to be coordinated with crews from the various power companies. Out-of-state power crews were brought in before and after the event to help with the restoration. One power company in Connecticut expected the cost of the restoration and cleanup from the storm to be about $100 million. Connecticut’s insurance commissioner estimated the storm costs in the Nutmeg State to be upwards of $500 million, with regional totals estimated at over $1.0 billion. While the main impact of the storm was the damage to the power grid, the wintry weather also resulted in flight and rail cancellations or delays, caused many vehicular accidents and was responsible for at least 22 deaths in the Northeast. In addition, new daily and monthly snowfall records were set, including 13.6 inches (34.5 cm) on the 29th at Concord, NH, and 9.1 inches (23.1 cm) on the 29th at Scranton, PA. Concord, NH’s monthly total of 23.0 inches (58.4 cm) blew away their previous monthly record snowfall total of 2.1 inches ( 5.3 cm).
  • For more information, please go to the Northeast Regional Climate Center Home Page.
  • Midwest Region: (Information provided by the Midwest Regional Climate Center)
  • October precipitation varied considerably across the Midwest. The western half of the region received below normal precipitation while the eastern half received above normal precipitation. Totals ranged from less than 25% of normal in parts of Missouri and Iowa to more than 200% of normal in parts of Ohio.
  • October temperatures fluctuated throughout the month. Despite starting the month with a couple days of cold temperatures, the first half of the month was above normal on average. The second half of the month was below normal despite having a brief warm spell. On average, the month was near normal for much of Missouri, Illinois, Indiana, and Ohio. Kentucky had below normal temperatures ranging to 2°F (1°C) below normal. Iowa, Minnesota, Wisconsin, and Michigan were slightly above normal for the month with temperatures up to 5°F (3°C) above normal.
  • Drought conditions in October improved in eastern Illinois and western Indiana but further west there was expansion and intensification of drought. The small area of moderate drought at the beginning of the month in northern Iowa and southern Minnesota expanded and intensified to severe drought by the end of the month. By the end of the month roughly 20% of Illinois, 40% of Minnesota, 50% of Missouri, and 70% of Iowa were designated in drought.
  • Two strong low pressure systems brought strong winds to the Great Lakes. On the 14th and 15th, low pressure centered in Canada brought strong northwest winds to the Great Lakes. Wind and wave warnings were issued on the lakes and power outages were scattered across the upper Midwest. On the 19th and 20th another low moved across Ohio and brought strong northeast winds to the Great Lakes. Winds in the Chicago area topped 50 miles/hour (80 km/hour) with gusts exceeding 60 miles/hour (95 km/hour). In both Chicago and Milwaukee, boats anchored near shore were battered by the waves sinking or washing ashore dozens of boats. Both cities also had windows blown out of high-rise buildings by the strong winds.
  • With the Missouri River back in its banks, boat traffic resumed along the river for the first time since June in both Iowa and Missouri. Road repairs were also ongoing with several stretches of Interstate 29 in western Iowa and northwest Missouri reopened in early October. Scores of levees, weakened or breached by the flood waters, were in various stages of repair in both states.
  • For details on the weather and climate events of the Midwest, see the weekly summaries in the MRCC Midwest Climate Watch page.
  • Southeast Region: (Information provided by the Southeast Regional Climate Center)
  • Mean temperatures in October were between 1 and 4 degrees F (0.5 and 2.2 degrees C) below average across most of the Southeast region, except along coastal sections of North Carolina and Virginia. Monthly temperatures were generally above average across Puerto Rico and the U.S. Virgin Islands. It was the coldest October ever observed at the summit of Mount Mitchell, NC in a record extending back to 1980. Across the Southeast, there were over 180 daily minimum and over 300 daily low maximum temperature records tied or broken during the month. Most of these records occurred in the wake of several cold frontal passages. Dulles Airport near Washington D.C. recorded a maximum temperature of 39 degrees F (3.9 degrees C) on the 29th of the month following a rare October snowstorm, making it the lowest maximum October temperature ever recorded in a record extending back to 1962.
  • Precipitation was highly variable across the Southeast in October. Monthly totals were at least 150 percent of normal across the Florida Peninsula, with some locations exceeding 300 percent of normal. Strong storms from the 7th to the 10th of the month dropped up to 17 inches (431.8 mm) of precipitation across central and southern Florida. It was the second wettest October on record in Vero Beach, FL, which recorded 21.93 inches (557.0 mm) for the month. Key West, FL recorded 17.14 inches (435.4 mm), making it the fourth wettest October on record. Most of this precipitation occurred over a 5-day period from the 15th to the 19th of the month. Significant flooding and property damage were reported. In contrast, October was unusually dry across most of Puerto Rico and the U.S. Virgin Islands. St. Thomas recorded just 1.95 inches (49.5 mm) of precipitation for the month, which was nearly 3.5 inches (88.9 mm) below average. The driest locations across the Southeast (less than 25 percent of normal) were found across Alabama and northwest Florida. Mobile, AL recorded just 0.09 inches (2.3 mm) of precipitation for the month. Elsewhere across the region, monthly precipitation was near normal to slightly above normal. A rare October snowstorm dumped up to 7 inches (177.8 mm) of snow across northern Virginia from the 28th to the 29th of the month, while higher elevations across the Southern Appalachians recorded up to 2 inches (50.8 mm). Dulles Airport recorded just its third measurable October snowfall ever with 0.6 inches (15.2 mm). On the 2nd of the month, Beech Mountain, NC recorded 0.5 inches (12.7 mm) of snow, making it the earliest measurable autumn snowfall on record in North Carolina.
  • There were 84 reports of severe weather across the Southeast in October, including 12 confirmed tornadoes. On the 9th of the month, an EF-1 tornado caused extensive damage to several homes on Fleming Island near Jacksonville, FL. A small outbreak of weak tornadoes occurred across eastern Virginia on the 13th of the month. Two of these tornadoes were caught on video by motorists as they crossed Interstate 95 and Highway 1 in Stafford and Prince William Counties. An EF-1 tornado damaged over 30 homes in a subdivision near Kent Lake, VA, while another EF-1 tornado in Louisa County caused major damage to the historic Sylvania Plantation house, which was built in 1746. The most severe tornado was an EF-2 that struck the Sunrise/Plantation area in Broward County, FL on the 18th of the month. This tornado caused damage to as many as 50 homes and several minor injuries were reported.
  • There were relatively few changes to the Drought Monitor in October. Extreme drought (D3) conditions continued across much of Georgia, eastern portions of Alabama, the upstate of South Carolina, and the western panhandle of Florida. There was a slight improvement from extreme (D3) to severe drought (D2) across parts of central and southern Georgia, while drought conditions were completely eliminated across most of the Florida Panhandle. Drought conditions expanded across Alabama, where precipitation deficits were the greatest.
  • 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)
  • The High Plains Region experienced a wide range of weather conditions this October including record warmth, record cold, severe storms, and snow. Overall, temperature departures generally ranged from near normal in the south up to 8.0 degrees F (4.4 degrees C) above normal in the north. Many locations across North Dakota ranked in the top 10 warmest Octobers on record. Fargo, North Dakota’s average temperature was 52.6 degrees F (11.4 degrees C) this month which was 7.3 degrees F (4.1 degrees C) above normal. That was warm enough to be ranked as the 6th warmest October on record (period of record 1881-2011). The warmest October on record, which was set in 1963, held firmly at 57.2 degrees F (14.0 degrees C). The hot, dry, and windy start to the month contributed to the warm average temperatures and also created dangerous fire weather conditions. Temperatures reached the mid to upper 90s throughout the Region and new daily temperature records were set in the Dakotas. One impressive record occurred at Dunn Center 1E, North Dakota, which is located north of Dickinson. The high temperature on October 4 was 98.0 degrees F (36.7 degrees C) which smashed the old record of 87.0 degrees (30.6 degrees C) set in 1963 (period of record 1919-2011). On the other end of the spectrum, Laramie, Wyoming set a new daily low temperature record of -16.0 degrees F (-26.7 degrees C) on October 27 after receiving some fresh snow. The old record of 0.0 degrees F (-17.8 degrees C) was set in 1996 (period of record 1948-2011).
  • Precipitation was highly variable this month across the High Plains Region. Little precipitation fell in the eastern part of the Region, along the eastern sides of North Dakota, South Dakota, Nebraska, and Kansas. Some locations in these areas were ranked in the top 10 driest Octobers on record. Although the dryness led to the development of abnormally dry and moderate drought conditions, the dry weather did help harvesting activities progress as many days were suitable for fieldwork. By the end of the month, the harvesting of most row crops was either completed or nearing completion. Extremely dry conditions were present early in the month and numerous fires were reported in Nebraska and South Dakota. These fires destroyed crops, combines, center pivots, and even homes. One fire in Stapleton, Nebraska, which is north of North Platte, burned over 25,000 acres and caused around $4 million in damages.
  • Meanwhile, other areas of the Region received over 200 percent of normal precipitation. These areas included central Nebraska, northwestern Kansas, pockets of Colorado, and southeastern and northwestern Wyoming. October 6-8 was an eventful time frame for many parts of the Region. Severe weather, including tornadoes, high winds, and hail were reported across southwestern Kansas on the 7th. Meanwhile, northwestern Kansas received high precipitation, most of which fell during the October 6-8 time frame as a slow moving system passed through the area. By the end of the month, a few locations had even surpassed 300 percent of normal precipitation. An extreme example was Hoxie, Kansas which received 6.95 inches (177 mm) of precipitation, most of which fell during the October 6-8 time period. Despite the monthly total for Hoxie being 5.81 inches (148 mm) above normal, or an impressive 610 percent above normal precipitation, this was only the 3rd wettest October on record (period of record 1897-2011). The wettest October on record occurred in 1946 with 7.55 inches (192 mm).
  • Parts of Wyoming were also wetter than normal this month. North central and southeastern Wyoming both had precipitation totals which were at least 200 percent of normal. Several locations ranked in the top 10 wettest Octobers on record and with 3.72 inches (94 mm) of precipitation, Sheridan, Wyoming had its wettest October on record (period of record 1907-2011). This monthly total was 2.31 inches (59 mm) above normal or 264 percent of normal precipitation. 1.79 inches (45 mm) fell in one day, October 7, and a new daily precipitation record was set as well. The old record occurred in 1993 with only 0.59 inches (15 mm).
  • In addition to heavy precipitation and severe storms, some of the first snow of the season affected parts of the Region. An early snow storm caused problems in Colorado. Leaves were still on trees as heavy, wet snow fell on October 26. As a result, trees fell causing many power outages. Snow totals were highly variable across north central Colorado, but with 11.5 inches (29 cm) of snow, Boulder, Colorado set a new daily snow record for October 26 (period of record 1893-2011). This crushed the old daily record of 4.1 inches (10 cm) set in 2006.
  • For more information, please go to the High Plains Regional Climate Center Home Page.
  • Southern Region: (Information provided by the Southern Regional Climate Center)
  • Average temperatures varied spatially in the Southern Region. In Mississippi, southern Tennessee, and south eastern Louisiana, temperatures were generally 2 to 4 degrees F (1.11 to 2.22 degrees C) below normal. Much of Arkansas and the remainder of Louisiana experienced a slightly cooler than normal October, while in Oklahoma and Texas, temperatures averaged between 2 to 4 degrees F (1.11 to 2.22 degrees C) above normal. The state average temperatures were as follows: 60.50 degrees F (15.83 degrees C) in Arkansas, 65.30 degrees F (18.50 degrees C) in Louisiana, 60.90 degrees F (16.06 degrees C) in Mississippi, 61.50 degrees F (16.39 degrees C) in Oklahoma, 56.40 degrees F (13.56 degrees C) in Tennessee, and 66.80 degrees F (19.33 degrees C) in Texas. For Mississippi, it was the twelfth coldest October on record (1895-2011), while Louisiana recorded its twentieth coldest October on record (1895-2011). In Tennessee it was the eighteenth coldest October on record (1895-2011).
  • With the exception of central Texas and eastern Tennessee, the bulk of the Southern Region experienced a very dry October. In central Texas, stations averaged between 100 and 250 percent of normal precipitation for the month. It is worth noting that these stations received between 4 to 8 inches (101.60 to 203.20 mm) of precipitation for the month. In eastern Tennessee, stations averaged between 100 to 200 percent of normal precipitation, or approximately 3 to 6 inches (76.20 to 152.4 mm) for the month. By contrast, conditions were extremely dry in Louisiana, Mississippi, eastern Texas, and southern Arkansas. Stations in southern Louisiana and southern Mississippi averaged only between 0 to 25 percent of normal, or approximately 3 to 5 inches (76.20 to 127.00 mm) less than they normally receive for the month. Louisiana averaged only 0.82 inches (20.83 mm) for the month, making it their ninth driest October on record (1895-2011). For Mississippi, it was the seventeenth driest October on record with an average precipitation total of 1.10 inches (27.94 mm). Other state average precipitation totals for the month include: Arkansas with 2.48 inches (62.99 mm) of precipitation, Oklahoma with 2.67 inches (67.82 mm) of precipitation, Tennessee with 2.39 inches (60.71 mm) of precipitation, and Texas with 2.18 inches (55.37 mm) of precipitation.
  • Over the month of October, drought conditions did not change much from September in Mississippi, Tennessee and Arkansas. Conditions have changed, however; in Texas, Oklahoma and Louisiana. In Oklahoma, much of the central portion of the state did see a one category improvement from exceptional drought to extreme drought. This was also the case for central Texas, where rainfall for the month was abundant. In Louisiana, the south east parishes went from being drought free to moderate drought. In addition, much of the western part of the state is now experiencing exceptional drought. In total for the Southern Region, there was a decrease in exceptional drought from 53.77 percent areal coverage to 41.90 percent areal coverage.
  • October was a quiet month for severe weather in the Southern Region. Less than half a dozen twisters were reported and there was very little in the way of hail or strong winds. The biggest outbreak of severe weather occurred on October 22, 2011, with several hail reports in central Oklahoma. Softball sized hail was reported in Okfuskee County, and some windshields were shattered by hail in Canadian County.
  • The bulk of weather impacts for the Southern Region continue to pertain to the longstanding Texas drought. The effects of the drought and wildfires on Texas agriculture have been devastating. Cotton has been particularly hard hit with a loss of more than half of the 7.1 million acres planted this season. With prices being extremely high, cotton crop losses alone have translated into a $1.8 billion loss to the Texas cotton industry. Precipitation during the second half of October helped to replenish livestock tanks and ponds and helped with the plating of fall crops and winter forages, but much more additional precipitation will be needed to maintain growth. Additionally, Texas corn farmers were expected to only harvest about half of the normal 200 million bushels the state normally produces each year. The devastating wildfire season has been estimated to have caused $200 million in damage to Texas agriculture alone. Overall, the $5.2 billion in estimated 2011 losses to Texas agriculture set in August have only increased since this estimate was put forth (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 Regional Climate Center)
  • October saw a startup of the winter storm season and the 2011-2012 water year. The first such storm arrived during the early days of October, followed by another significant event about mid-month, and providing above normal precipitation for much of the West. Temperatures were near normal throughout most of the West, with areas of above normal temperatures throughout Montana, Wyoming, eastern California, Nevada, and southern Arizona.
  • The greatest positive temperature anomalies this October occurred in eastern Montana, northern Wyoming, and southern Arizona. Tucson’s October average was 83.3 F (28.5 C), the 13th warmest October on record. Billings, Montana experienced a monthly average of 51.9 F (11 C), the 9th warmest October since 1948. In the midst of warm October temperatures in the inland Northwest, record low temperatures on individual days were recorded with the passage of cold fronts. On October 27th Laramie, Wyoming had a record low of -16 F (-26.7 C), shattering the previous daily record of 7 F (-13.9 C) set in 1970.
  • Precipitation was near normal for most of the West, with pockets above normal. Many above normal values were recorded in the inland Northwest, setting or tying previous precipitation records. Missoula, Montana experienced its 4th wettest October on record with a rainfall total of 2.4 in (60.9 mm). Pocatello, Idaho and Boise, Idaho both experienced their 6th wettest Octobers on record with rainfall totals of 1.99 in (50.5 mm) and 1.79 in (45.5 mm) respectively. One of the most impressive records occurred at Riverton, Wyoming on October 8th. Riverton received a daily total of 1.14 in (29 mm) rainfall, well beyond the previous record for the date of 0.11 in (2.8 mm) set in 2010, and above the October monthly average at that location of 0.91 in (23 mm).
  • Western Oregon and southern Arizona and New Mexico were drier than normal at most stations. October 2011 was the 16th driest year on record at Eugene, Oregon airport, with a precipitation total of 1.81 in (46 mm), or 51% of the 3.54 in (90 mm) October average. Tucson, Arizona received 0.06 in (1.5 mm), only 7% of the average 0.87 in (22 mm) for that location, making it the 29th driest October on record at Tucson. The low precipitation in the Southwest allowed drought conditions and extent to persist for Arizona and New Mexico throughout October.
  • October 6-8: Winter Storm: The first winter storm of the 2011-2012 water year passed through the West October 6th through 8th, providing precipitation throughout the region and dropping 1 to 2 ft (30.5 cm-61.0 cm) of snow at some locations the Sierra and Rockies.
  • October 26, 27: Colorado Snowstorms: Heavy snowstorms dropped up to 18 in (45.7 cm) of snow in the foothills west of Denver, and 5-8 in (12.7 cm-20.3 cm) in the Denver metropolitan area. The heavy, wet snow felled many trees leaving 200,000 without power.
  • October (all month) Late first freezes: Warm temperatures dominated throughout the West in October. Many locations saw much later than average first freezes. Ely, Nevada experienced its first freeze October 5. The only later freeze at that location was October 13, 1963. Spokane, Washington and Boise, Idaho experienced their first freezes on October 25, more than two weeks later than their average freezes of October 8th and October 10th respectively.
  • For more information, please go to the Western Regional Climate Center Home Page.

See NCDC's Monthly Records web-page for weather and climate records for the most recent month. For additional national, regional, and statewide data and graphics from 1895-present, for any period, please visit the Climate at a Glance page.


PLEASE NOTE: All of the temperature and precipitation ranks and values are based on preliminary data. The ranks will change when the final data are processed, but will not be replaced on these pages. Graphics based on final data are provided on the Temperature and Precipitation Maps page and the Climate at a Glance page as they become available.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: National Overview for October 2011, published online November 2011, retrieved on September 2, 2014 from http://www.ncdc.noaa.gov/sotc/national/2011/10.