National Overview - August 2010
Maps and Graphics
Temperature and Precipitation Ranks
U.S. Percentage Areas
The weather pattern for August 2010 was a continuation of the pattern which has dominated this summer. The North Atlantic high pressure system held sway over much of the eastern and southern United States, bringing sunny skies and much above-normal temperatures, while dips — or troughs — in the upper-level jet stream kept above-normal temperatures from dominating much of the U.S. Hundreds of daily maximum temperature records were tied or broken at individual stations, while over 6,000 daily records were tied or broken for warmest daily minimum temperature during August 2010, with the month ranking in the top ten warmest category for several Great Lakes and southern states.
While the North Atlantic high (also known as the Bermuda High) dominated in the South, the jet stream was active across the northern tier states. A number of summertime low pressure systems and cool fronts brought areas of rain to the north and severe weather to Minnesota. Over 2,000 daily precipitation records were tied or broken at individual stations. But precipitation in the northern states, as well as across the rest of the country, was spotty — typical of late summer. Moisture from a dissipated Gulf of Mexico tropical depression, and a few cold fronts that penetrated into the southern states, brought scattered showers and thunderstorms to the South, but a large swath of the country from Texas to the southern Great Lakes and Mid-Atlantic was drier than normal. The warm and dry weather resulted in an expansion of abnormally dry (D0) to extreme drought (D3) conditions in this area.
The unusual warmth during this summer (June-August) resulted in a record-high energy demand for cooling, as measured by NOAA's Residential Energy Demand Temperature Index (REDTI). The summer warmth (especially the widespread occurrence of warm daily lows), combined with an above-average extent of days with precipitation and days with heavy precipitation, contributed to NOAA's Climate Extremes Index (CEI) being about one-and-a-half greater than its historical summer average.
- Temperature Highlights - August
- Persistently strong high pressure continued to dominate the weather pattern in the U.S. during August 2010. This was the seventh warmest August on record with a temperature that was 2.2°F above the long-term average.
- The majority of the U.S. had above-average temperatures during August. Florida, Louisiana (tied) and Tennessee (tied) each had their second warmest August on record. Fourteen other states had an August temperature among their warmest ten percent. No state experienced an average temperature significantly below its long term average.
- Regionally, the Southeast had its third warmest August on record, while it was the seventh warmest in the South and the eighth warmest in the East North Central. Of the nine climate regions in the contiguous U.S., only the West and Northwest observed near normal August temperatures.
- Summer (June through August) and Year-to-Date
- Nationally, it was the fourth warmest summer on record.
- Three climate regions had top-five warm summers: the Southeast (warmest), the Central (3rd warmest) and the Northeast (4th warmest).
- Abnormal warmth dominated the much of the East, where ten states experienced record-warm summers: Rhode Island, New Jersey, Delaware, Maryland, Virginia, North Carolina, Tennessee, South Carolina, Georgia, and Alabama. Nineteen other states experienced average temperatures classified as "much above normal".
- Several cities broke summer temperature records, including: New York (Central Park), NY; Philadelphia, PA; Trenton, NJ; Wilmington, DE; Tallahassee, FL (ties 1998); and Asheville, NC.
- The Northeast climate region experienced its warmest January-August period with an average temperature more than 3.4 degrees F above the long term average.
- Maine, New Hampshire, Vermont, Rhode Island, Connecticut, and New Jersey each had their warmest year-to-date period. All Northeastern states ranked among their warmest ten percent of the record. Only Florida and Texas had below-normal temperatures for the period.
- Precipitation Highlights - August
- August precipitation was highly variable across the contiguous United States, typical of a late-summer weather pattern. The
number of states (11) with below normal precipitation equaled the number of states with above normal precipitation, but the overall national average was below normal. Indiana had its third driest August on record.
- Summer (June through August) and Year-to-Date
- The summer storm pattern brought significant precipitation to the Upper Midwest. Wisconsin had its wettest summer on record: 6.91 inches above its average. Several states in the region had a top-ten wettest summer: Michigan (3rd wettest), Iowa (3rd), Illinois (6th), Nebraska (6th), South Dakota (9th), and Minnesota (10th). The East North Central climate region had its second wettest summer on record, and the nationally averaged precipitation was above average.
- A persistent high pressure system and the lack of any significant tropical weather during the summer months contributed to below average precipitation in much of the Southeast and Mid-Atlantic. Long-term dryness in the Mid-Atlantic led to the development of severe drought in parts of Virginia, Maryland, and West Virginia.
- Heavy rainfall during the summer months across the Upper Midwest helped diminish rainfall deficits from the first five months of the year.
- Wetness during the first 8 months of 2010 in the northern Plains was offset by below average precipitation across a wide swath of the Southeast and Mid-Atlantic. The nationally-averaged precipitation for the period was near normal. Dryness has persisted throughout 2010 in Louisiana, where parts of the state have been in drought since April.
- The year-to-date precipitation was much above average in the East North Central (5th wettest) and the West North Central (10th wettest) regions. Iowa experienced its 3rd wettest January-August and South Dakota its 9th wettest. Wisconsin and Nebraska also experienced much above average precipitation for the year-to-date period.
- Other Items of Note
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand for Summer 2010 was the highest of the 116-year record, and eighth-highest for August itself. The unusual warmth in the highly populated mid-Atlantic and Southeast contributed to the highest Summer REDTI value on record
- Tornado activity across the U.S. during August was slightly below average. However numerous August tornadoes in Minnesota, combined with an active summer, will likely help break the state's annual tornado record of 74, which was set in 2001.
- NCDC's Climate Extremes Index (CEI) for Summer 2010 was about one-and-a-half times its historical average. The CEI measures the occurrence of several types of climate extremes (like record or near-record warmth, dry spells, or rainy periods). Factors contributing to this summer's value: a very large area with extreme warm low temperatures (six times larger than average footprint; the largest since 1910), an above-average extent of days with precipitation and days with heavy precipitation.
- The U.S. Drought Monitor reported 9.6 percent of the contiguous United States was affected by drought on August 31st. Late-summer dryness intensified across the Mid-South, resulting in a broad expansion or development of abnormal dryness and moderate drought. Abnormal dryness (D0) significantly expanded in Illinois, Indiana, Michigan, and Ohio where pastureland was rated in very poor to poor condition. Slight improvements were seen along the east coast and southern New England.
- Wildfire activity during both August and the 2010 year-to-date period was exceptionally quiet. The acreage burned during August was the lowest in 11 years and the acres burned during the year-to-date period was less than half the long term average.
Alaska Temperature and Precipitation:
Beginning with January 2010 processing, the Alaska temperature and precipitation report is comprised of several datasets at NCDC, integrating GHCN and COOP datasets. Prior to 2010, the Alaskan temperature timeseries was processed with just GHCN data.
- Alaska had its 22nd warmest August since records began in 1918, with a temperature 1.1°F (0.6°C) above the 1971–2000 average.
- Alaska had its 47th warmest June–August on record, with a temperature 0.4°F (0.2°C) below to the 1971–2000 average.
- Alaska had its 23rd warmest year–to–date on record, with a temperature 0.9°F (0.5°C) above the 1971–2000 average.
- Alaska had its 33rd driest August since records began in 1918, with an anomaly that was 4.8 percent below the 1971–2000 average.
- Alaska had its 23rd wettest June–August on record, with an anomaly that was 11.6 percent above the 1971–2000 average.
- Alaska had its 25th driest year–to–date on record, with an anomaly that was 4.6 percent below the 1971–2000 average.
For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below and visit the Climate Summary page. 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.
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)
- While August was not as steamy as July, the run of above normal temperatures that began in January continued. With an average of 69.8 degrees F (21.0 degrees C), the Northeast had its 8th consecutive warmer than normal month. In addition, it was the 6th month in a row with all states posting above normal averages. The regional temperature departure of 1.8 degrees F (1.0 degrees C) above normal was only 0.1 degree F (0.1 degrees C) warmer than August 2009. Departures among the states ranged from 1.0 degree F (0.6 degrees C) above normal in New Hampshire and Vermont to 2.8 degrees F (1.6 degrees C) above normal in West Virginia. Three states had monthly averages in the top 20 since 1895: West Virginia, 12th; New Jersey, 15th; and Delaware, 18th. It was the 22nd warmest August in 116 years in the Northeast.. Four states in the region - Delaware, Maryland, New Jersey and Rhode Island - had their warmest summer (June through August) since 1895. In addition, it was the 2nd warmest in Massachusetts and West Virginia; the Northeast also placed 2nd warmest with a 3-month average of 70.0 degrees F (21.1 degrees C).
- August averaged on the dry side in the Northeast. The regional total of 3.51 inches (89.2 mm) was 89 percent of normal and 0.43 inches (10.9 mm) less than the same month in 2009. It was the driest August since 2002. Three states — Maryland (102 percent), Massachusetts (105 percent) and New York (114 percent) had above normal totals; departures in the remaining states ranged from 51 percent of normal in New Jersey to 96 percent of normal in Vermont. New Jersey had its 15th driest August since 1895. The summer of 2010 averaged near normal in the Northeast. The three-month average of 11.62 inches (295.1 mm) was 96 percent of the normal amount. New Jersey had its 15th driest summer in 116 years with only 67 percent of the normal summer rainfall. Of the 12 states in the region, New York had the wettest summer, with 113 percent of normal precipitation.
- The drought situation changed slightly in a month as indicated in the August 31, 2010 U. S. Drought Monitor. By the end of August, portions of east central Maine were seeing moderate drought conditions (D1) and abnormally dry conditions (D0) were present in the rest of the state except for coastal Maine, which was normal. D0 conditions expanded in New Hampshire and West Virginia, but conditions improved in most of Pennsylvania. In West Virginia, severe drought conditions (D2) expanded into eastern Mineral and all of Hampshire and Handy Counties in the eastern panhandle, while D1 conditions stretched into Preston, Tucker and Pendleton Counties. In New York, rainfall eased the abnormally dry conditions in the southern Hudson Valley, but the lack of rain along the coast led to D1 conditions in central portions of Long Island. Conditions in the western Maryland panhandle deteriorated from D0 at the end of July to D1 on August 31st, while southeastern Maryland saw improvement from D2 to D1 conditions in Wicomico, Worcester and Somerset Counties.
- Warm and dry weather impacted crops and pastures in West Virginia, Maryland and Delaware, with reports of reduced yields and conditions mainly ranging from poor to fair. Conditions elsewhere in the region were not as bad, with most crop progress ahead of normal and in fair to excellent condition, especially fruit and vegetables with access to irrigation.
- While the agricultural industry suffered in parts of the Northeast, the tourist industry benefitted from terrific vacationing weather. The New Hampshire State Climatologist reported that "the nearly perfect weather conditions this August lead to an increase in tourism revenue, compared to the disappointing summer 2009 season, including an increase in hotel occupancy, with packed beaches and state parks."
- For more information, please go to the Northeast Regional Climate Center Home Page.
- Midwest Region: (Information provided by the Midwest Regional Climate Center)
- August was warm across the Midwest with temperatures ranging from 2 degrees F (1 degrees C) to 5 degrees F (3 degrees C) above normal. Daily temperature records were skewed strongly towards record highs (over 1000) versus record lows (less than 100) for the month. Summer (June, July, and August) temperatures were also above normal. Departures ranged from near normal in the northwest parts of the Midwest up to 4 degrees F (2 degrees C) above normal in parts of Kentucky and southern Missouri. The summer warmth was consistent across the region, as the only state to report below normal temperatures for a summer month was Minnesota in June.
- August precipitation ranged from less than 50 percent of normal to more than 200 percent of normal. Several states reported both extremes. There were three areas that reported over 150 percent of normal, southern Kentucky, central and southeast Iowa, and from central Minnesota into northwest Wisconsin. There were also three areas reporting less than 50 percent of normal precipitation, southern Missouri, southern Indiana, and southern Michigan. Summer precipitation was more than double the normal amount in a swath that included northwest, central, and southeast Iowa, northeast Missouri, and west central Illinois. Parts of central and southeast Iowa topped 30 inches (760 mm) of seasonal rainfall. Most of the region was above normal with only southern Missouri and the lower Ohio River valley less than 75 percent of normal for the summer. La Crosse, Wisconsin recorded its wettest summer on record (138 years) with 20.93 inches (532 mm). Iowa's statewide precipitation total of 23.23 inches (590 mm) for the summer was second (of 138 years) only to 1993's 26.83 inches (681 mm).
- Summer of 2010 weather patterns spawned numerous tornadoes in Minnesota and Wisconsin. Although final counts are still pending, Minnesota is likely to set a new state record for number of tornadoes and Wisconsin is likely to rank 2010 as the third busiest year. The storms were not only numerous but also strong. On June 17th Minnesota was hit with three EF4 tornadoes. The strong twisters were the first classified as EF4 in Minnesota since 2000 and the first time since 1967 that three EF4 tornadoes were recorded on the same day in Minnesota. Iowa tornado totals are likely to end up below normal however.
- Drier weather for the latter half of August was welcomed in flood weary Iowa. The break from their rainy summer pattern allowed rivers to recede back into their banks with only the lower Des Moines River remaining above flood stage, but falling, by the end of August.
- Dry weather in the southern and eastern parts of the Midwest has led to the introduction of drought and large areas of abnormally dry conditions in the US Drought Monitor.
- 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 for August 2010 were above normal across the Southeast. Departures from normal ranged from 1-3 degrees F (0.5-1.6 degrees C) above normal near the coasts (including Puerto Rico) to 5-6 degrees F (2.7-3.3 degrees C) above normal across portions of central Alabama and North Carolina. Over 20 locations experienced their warmest August on record, including Gainesville, FL, Columbus, GA, Greensboro, NC, Charleston, SC, and Greenville, SC. Much of the overall warmth observed across the region since April can be tied to exceptionally warm overnight temperatures. This was again the case in August, with over 1,800 record daily high minimum temperatures tied or broken during the month. Atmospheric water vapor contents were unusually high in August across much of the Southeast and this contributed to the warm overnight temperatures and greater rainfall (see below). The end of August marked one of the warmest meteorological summers (June-August) on record across a large portion of the Southeast. Over 150 locations in the region experienced their warmest summer on record, including Miami, FL, Washington, D.C., Greensboro, NC, Roanoke, VA, Birmingham, AL, and Charleston, SC. The anomalous warmth this summer, particularly overnight, resulted in significant increases in air conditioning cooling demand. In Atlanta, GA, for example, cooling demand was 28 percent above normal for the summer, up from 23 percent last summer.
- Monthly precipitation was highly variable across the Southeast in August. In particular, there was a marked increase from July in the areal coverage of above average precipitation. The wettest locations were found through central portions of Virginia and North Carolina, eastern South Carolina, central and southern Georgia, western Alabama, and southern Florida, where precipitation for the month was between 200 and 300 percent of normal. Along coastal sections of Alabama and western Florida, the remnants of Tropical Depression Five brought heavy rain over a three-day period in the middle of the month. More than 4 inches (101.6 mm) of rain fell near Mobile, AL, resulting in major flooding and disruption to the city's water supply system. The storm had earlier produced heavy rain and severe weather over Florida prior to becoming a tropical depression. In particular, Bradenton, FL, recorded a monthly record 24-hr rainfall of 6.12 inches (155.45 mm) on the 8th of the month, which broke the old record by over two inches. The driest locations across the Southeast in August (less than 50 percent of normal) were in southeastern portions of Virginia and North Carolina, southwest North Carolina, and eastern portions of Alabama and Florida. Monthly precipitation was highly variable across Puerto Rico (200 percent of normal across the northern half of the island to less than 50 percent across the southern half). The summer rainfall total of 26.15 inches (664.21 mm) recorded at San Juan Airport was just 0.03 inches (0.76 mm) shy of breaking the old record set back in 1950. In contrast, there were many locations in the Southeast that experienced significant summer season precipitation deficits. It was the third driest summer ever and the driest in over 80 years in the Richmond, VA area, in a record extending back to 1887. The Orlando, FL area experienced its driest summer ever in a record extending back to 1948 with just 13.11 inches (332.99 mm).
- There were 508 reports of severe weather across the Southeast in August with high winds comprising 94 percent of the reports. Most of these reports were associated with a series of squall lines that moved southeast across Virginia and the Carolinas ahead of a cold front on the 5th and 6th of the month. This outbreak also spawned an EF0 tornado in central South Carolina (Orangeburg County) that caused some minor tree damage. The remaining tornado reports occurred in Florida on the 8th of the month in connection with the band of thunderstorms that would eventually develop into Tropical Depression Five. An EF0 was reported in Volusia County south of Daytona Beach, while a weak tornado was reported near Boca Raton. Both resulted in extensive roof damage to homes and buildings.
- The beneficial rainfall in August helped ameliorate drought conditions in many parts of the Southeast, though roughly half the region still displayed D0 or greater conditions by the end of the month. The most notable change in the Drought Monitor occurred through central portions of Virginia and North Carolina, where regions of moderate drought (D1) were completely eliminated. Conditions in western North Carolina and northwest South Carolina improved from D1 to abnormally dry (D0), while D0 conditions in northern Alabama, Georgia, and southeast South Carolina were also eliminated. Unfortunately, the beneficial August rains did not extend to the driest parts of the region. Severe drought (D2) continued to be observed across large portions of eastern Virginia, with moderate drought (D1) persisting across much of southeastern North Carolina. This has resulted in a loss of up to 80 percent in corn crop yields in the region and further reductions in soybean, cotton, and peanuts. In addition, the increased rainfall coupled with warm temperatures in Georgia lead to one of the worst infestations of army worms and white mold in hayfields and pastures in more than 25 years.
- 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)
- Temperature departures across the eastern half of the Region ranged from 2-4 degrees F (1.1-2.2 degrees C) above normal and isolated areas of Colorado, Kansas, Nebraska, and South Dakota were 4-6 degrees F (2.2-3.3 degrees C) above normal. The warmer than normal temperatures were not hot enough to break records, although a few locations in Colorado and Kansas were able to break into the top 10 warmest Augusts on record. This month's warm spot was Alamosa, Colorado which is located in the south central portion of the state. Alamosa had its 9th warmest August on record (period of record 1906-2010) with an average temperature of 64.4 degrees F (18.0 degrees C).
- Overall, the summer (June, July, and August) was also warmer than normal for many locations in the Region, especially Colorado and Kansas where temperature departures were 2-4 degrees F (1.1-2.2 degrees C) above normal. Alamosa, Colorado recorded its warmest summer on record with an average temperature of 64.4 degrees F (18.0 degrees C). The previous warmest summer on record was set in 2007 with an average temperature of 64.1 degrees F (17.8 degrees C). Wichita, Kansas recorded its 5th warmest summer on record (period of record 1888-2010) with an average temperature of 82.3 degrees F (27.9 degrees C). The warmest summer on record in Wichita occurred in both 1936 and 1934 with an average temperature of 85.3 degrees F (29.6 degrees C).
- Precipitation was spotty across the High Plains Region this month. Some areas of the Region, including central South Dakota, northern Nebraska, eastern and west central Kansas, and central and eastern Wyoming, received precipitation which was only 50 percent of normal or less. Meanwhile, other areas including southeastern South Dakota, eastern Colorado into southwestern Nebraska, and central Kansas received greater than 150 percent of normal precipitation. These precipitation totals were not enough to break records in August, however new precipitation records were set for the summer.
- This month's wet spot was Wessington Springs, South Dakota. Wessington Springs received 3.95 inches (100.33 mm) of precipitation, or 178 percent of normal, which was the 9th wettest August on record (period of record 1893-2010). For the summer, Wessington Springs received a total of 25.16 inches (639.07 mm) of precipitation which smashed the old record of 15.52 inches (394.21 mm) received in 1962. Interestingly, the heavy precipitation this year now totals 35.43 inches (899.92 mm) which sets a new record for the entire year! The previous record was 34.13 inches (866.90 mm) of precipitation received in 1995.
- The high precipitation led to flooding along rivers for much of the summer. According to the National Weather Service in Valley, NE, the Missouri River at Brownville was above flood stage for 78 consecutive days from June 11th to August 28th. The river crested at 42.89 feet, or 10.89 feet above flood stage, on June 22nd and this was the second highest crest ever reported at Brownville. The highest crest occurred July 24, 1993 with a stage of 44.30 feet.
- While overall, summer 2010 was wet for many locations across the High Plains Region, some locations were drier than normal which led to significant changes in the U.S. Drought Monitor this month. Early in the month, pockets of abnormally dry conditions (D0) were introduced to north central South Dakota, southeastern Nebraska, and northern Kansas. Later in the month, moderate drought conditions (D2) developed in north central South Dakota as little rain fell and D0 conditions were also expanded into North Dakota. Meanwhile, drought conditions remain unchanged in Wyoming and the D0 area in Colorado was trimmed slightly. According to the U.S. Seasonal Drought Outlook released August 19th, the drought conditions in western Wyoming were expected to persist through November 2010.
- For more information, please go to the High Plains Regional Climate Center Home Page.
- Southern Region: (Information provided by the Southern Regional Climate Center)
- August was a very warm month throughout the Southern Region (See Figure 1). The highest departures from normal were observed in Arkansas, eastern Oklahoma, northeastern Texas, northern Mississippi and western Tennessee. Most stations in the region reported average monthly temperatures that ranged from 2-6 degrees F (1.11-3.33 degrees C) above expected normals, while some stations reported as high as 8 degrees F (4.44 degrees C) above normal. Louisiana reported a state-wide average temperature of 84.9 degrees F (29.39 degrees C), which was the second warmest August on record (1895-2010). This monthly average was also tied for the third warmest month in Louisiana (1895-2010). Tennessee also reported its second warmest August on record (1895-2010) with an average temperature of 80.10 degrees F (26.72 degrees C). Elsewhere, Arkansas reported its eighth warmest August (1895-2010) with a state average temperature of 83.90 degrees F (28.83 degrees C), while in Texas, temperatures averaged 84.40 degrees F (29.11 degrees C), which was the ninth warmest August on record (1895-2010). The state-wide average August temperature for Mississippi was 83.50 degrees F (28.61 degrees C), or the ninth warmest August on record (1895-2010). In Oklahoma, it was the sixteenth warmest August on record (1895-2010) with an average state temperature of 83.80 degrees F (28.78 degrees C). In total, the Southern Region's weighted average temperature was 83.89 degrees F (28.83 degrees C), which is the fourth warmest August on record (1895-2010).
- August precipitation totals varied significantly throughout the Southern Region (see Figure 2). In general, the majority of the region experienced a drier than normal month, however; there were some areas where it was quite wet. For example, in southern Mississippi, southern Louisiana and eastern Louisiana, many stations reported precipitation totals that varied from 150 to over 200 percent of normal. Similar values were also observed in the western panhandle of Texas, in northern and central Tennessee and in north central Oklahoma. Some of the wettest areas of the region included Prentiss, Mississippi, which reported 14.01 inches (355.85 mm) of precipitation, or 10.65 inches (270.51 mm) above the monthly normal. This was the wettest August on record for that station (1940-2010). McComb, Mississippi reported 12.30 inches (312.42 mm) of precipitation, which was 7.11 inches (180.59 mm) above normal, and the second wettest August on record (1949-2010) for that station. In Ocean Springs, Mississippi, a total of 17.23 inches (437.64 mm) of precipitation was reported for the month. Normals for Ocean Springs are not available. By contrast, conditions were quite dry in southern Texas, with the majority of stations reporting less than five percent of the monthly normal. In fact, some stations did not receive any rainfall for the entire month. Some examples include San Manuel, Mercedes 6 SSE, La Joya, Eagle Pass and Calliham. The state of Texas averaged 1.23 inches (31.24 mm) of precipitation for the month, which was the twenty-first driest August on record (1895-2010). Conditions were also quite dry in southern Oklahoma and northeastern Arkansas, where most stations reported less than a quarter of the monthly normal. Arkansas averaged 1.75 inches (44.45 mm) of precipitation for the month, which was the fifteenth driest August on record (1895-2010). In northern Mississippi, conditions were also dry, with the majority of stations reporting between 50 to 70 percent of normal for the month.
- Drought conditions in the Southern Region have changed significantly over the past month. Due to dry conditions throughout most of Arkansas, much of the eastern and northern areas of the state are now classified as being in moderate drought conditions. In Texas, a new area of moderate drought has been designated within and about the Edwards Plateau Climate Division. In addition, much of central Texas is now observing abnormally dry conditions, meaning that if dry conditions do not improve, drought could be observed in the very near future. Elsewhere, drought conditions have not changed significantly. In total, 21.8 percent of the Southern Region is now experiencing moderate drought, which is 10.3 percent higher than the start of last month.
- In terms of severe weather, there were dozens of wind reports on August, 15, 2010. This included the regions of central and southwestern Mississippi. Damage from the winds included downed trees, limbs and power lines. A similar occurrence was observed on September 22, 2010, in the regions of northern Louisiana, southern Arkansas, and central Mississippi.
- In Texas, excessive heat gripped the state through most of the month. Unfortunately, there were several reports of heat-related deaths, including at least 3 small children that were left in vehicles for prolonged periods of time. The heat caused electricity usage in Texas to reach a new record level of 65,715 megawatts on August 30, 2010, the fourth straight week of record-setting usage in Texas. (Provided by Texas State Climate Office)
- Reports of grassfires increased as the month progressed, as dry conditions turned vegetation that grew during a moisture-rich first 7 months of 2010 into kindling. By the end of the month, 80 Texas counties had burn bans including Austin, Brownsville, Fort Worth, and San Angelo. (Provided by Texas State Climate Office)
- Severe weather was limited during the month, but thunderstorms caused extensive damage to roofs of several buildings in Bastrop County on the 16th. A slow moving thunderstorm in the Houston area on August 23, 2010 left 100,000 customers without power in Sugar Land and surrounding areas. Numerous downed trees and power lines were reported in Sherman as hurricane force winds accompanied a severe thunderstorm. The following day thunderstorm winds knocked down trees and power lines in Northwest Waco. (Provided by Texas State Climate Office)
- For more information, please go to the Southern Regional Climate Center Home Page.
- Western Region: (Information provided by the Western Regional Climate Center)
- Temperatures were moderately above normal in the western High Plains, Southern Rockies, and New Mexico and Arizona. They were slightly cooler than normal in the northwest quarter of the region, and in central California and all along the West Coast. Coastal California continued its foggy summer, one of the coolest on record, up until the 24th when the first brief summer heat wave finally arrived. Until then, San Diego had recorded all but one day with below normal temperatures for the month as had San Francisco to the north. From May 1st until the 71 degrees (21.6 degrees C) degree reading on August 23rd, Bodega Bay, California, had failed to rise above 64 degrees F (17.8 degrees C). Eureka, California, has had only one day with a temperature of 70 degrees F (21.1 degrees C) or higher (73 degrees F on August 24th) from May through August. The month and summer have been the coolest in a decade along the California coast, and the coolest since 1982 in San Jose. Daytime maximum temperatures have been notably low, and in San Diego were the coldest since 1933. By contrast, Clayton, New Mexico saw its 2nd warmest August since 1897.
- Precipitation patterns were mixed as well. The West Coast and Sierra/Cascades were dry but the intermountain region had pockets of above and below normal rainfall. The Four Corners region of the Southwest had a definite positive departure for the month. The monsoon season has been active near the Arizona/New Mexico border. Parts of northern Arizona experienced a very wet July and August. The 9.45 inches (240 mm) of rain in Flagstaff was the wettest July-August total in Flagstaff since 1986. Some automated stations in Arizona received nearly 16 inches (406 mm) of rain for these two months. Billings, Montana recorded its 2nd wettest August since 1934, with 2.78 inches (71 mm), and 2nd wettest summer (Jun-Aug) with its 9.58 inches (243 mm) just shy of the 1944 record of 9.90 inches (251 mm). Conversely, the Pacific Northwest rainfall totals for July and August have been well below average with Seattle's July and August total at roughly 30 percent of normal. The first snows of the new winter coated the mountaintops of southwest Montana on the 22nd.
- August 8: Thunderstorms in Las Vegas Area: Several cars were dented by 1 inch diameter hail during the evening hours near the town of Moapa. A house in Las Vegas was struck by lightning causing a fire that completely destroyed the residence. Estimated damage was $200,000.
- August 23-26: Excessive Heat in Southern California: Temperatures of over 110 degrees F (43.3 C) were recorded in portions of Los Angeles County and other areas of Southern California. Some strong thunderstorms formed in the mountainous areas on the 25th with heavy rain, hail and strong winds. Flooding and mudflows caused temporary closing of some mountain highways. Ten power poles were knocked down by thunderstorm winds in Lake Elsinore causing live wires to fall onto a bus trapping the driver and 11 passengers for two hours on the 25th. More thunderstorms on the 26th produced local flooding and road closures. Near Lucerne Valley three people in a car were washed away during one flood event but were eventually rescued as 1.73 inches (44 mm) of rain fell in a 90-minute period.
See NCDC's Monthly Records web-page for weather and climate records for the month of May. 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.