September 2008 National Climate Report

• The average September temperature of 65.8°F (18.8°C) was 0.4°F (0.2°C) above the 20th century average and ranked as the 49th warmest September on record, based on preliminary data.

• On the Regional level, much of the U.S. experienced near normal temperatures during September. The South region had below average temperatures and the West region experienced above average temperatures.

• Using the Residential Energy Demand Temperature Index (REDTI - an index developed at NOAA to relate energy usage to climate), the nation's residential energy demand during September was approximately 1.7 percent below average consumption and ranked as the 40th lowest in 114 years.

• Precipitation across the contiguous United States in September averaged 2.68 inches (68 mm), which is 0.20 inch (5 mm) above the 1901-2000 average. This was the 38th wettest September in the 1895—2008 record.

• September was the 3rd driest on record for the West region and the 15th wettest for the South region. Much of the Central, East North Central, and Northeast regions experienced above-average precipitation during the month.

• ENSO-neutral conditions were present in the equatorial Pacific Ocean by the end of September. Equatorial sea-surface temperature anomalies have decreased in the east-central and eastern Pacific. Based upon recent trends and models, the CPC is forecasting ENSO-neutral conditions to continue through the Northern Hemisphere spring 2009. These conditions increase the probability of above normal temperatures for much of the western and midwestern U.S. The conditions also increase the chances of above normal precipitation for the Southwest. For additional information on ENSO conditions, please visit the NCDC ENSO Monitoring page and the latest NOAA ENSO Advisory.

• Alaska had its 25th warmest September since records began in 1918, with a temperature 1.1°F (0.6°C) above the 1971—2000 average.
  
  
• Alaska had its 45th warmest July—September on record, with a temperature 0.5°F (0.3°C) below the 1971—2000 average.
  
  
• Alaska had its 35th warmest January—September on record, with a temperature 0.2°F (0.1°C) 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 September Climate Summary page. For information on local temperature and precipitation records during the month of September, please visit NCDC's Extremes page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.

• The Northeast temperature average for September 2008 was 62.1°F (16.7°C). This was 1.9°F (1.7°C) above normal and 0.9°F (0.5°C) cooler than September 2007. Each of the 12 states in the region averaged above normal this month. Vermont was the warmest state, with a departure of 2.6°F (1.4°C) above normal and Maryland's temperature average was the closest to normal, only 0.7°F (0.4°C) above the 30-year mean.
  
  
• Overall, the Northeast averaged 4.65 inches (118 mm) of rain, or 117 percent of normal, but totals were quite variable from east to west. Two tropical systems (Hannah and Kyle) brought abundant rainfall to the coastal regions, leaving interior sections high and dry. Southern New England saw the most precipitation, with Rhode Island reporting the greatest amount, 9.36 inches (238 mm) (246 percent of normal). Massachusetts's total of 8.27 inches (210 mm) was 209 percent of normal, and Connecticut's 9.12 inches (232 mm) was 208 percent of normal. It was the 2nd wettest September since 1895 in Rhode Island, the 4th wettest in Massachusetts, and the 5th wettest in Connecticut. West Virginia was the driest state, with only 58 percent of the normal September rainfall. Vermont and New York also averaged on the dry side, 83 and 87 percent of normal, respectively.
  
  
• Drought conditions improved since last month in coastal areas, but worsened in a few interior locations. According to the September 30, 2008 Drought Monitor, southern West Virginia and a small area in north-central Pennsylvania were experiencing moderate drought, while most of the rest of West Virginia, northwestern Pennsylvania, southern New Jersey, Delaware and the northern half of Maryland's Eastern Shore were abnormally dry. All of New England as well as the Champlain and Hudson Valleys of New York were experiencing unusual to extremely moist conditions, according to the Palmer Drought Severity Index.
  

• Temperatures this month were below normal in the southwestern portions of the region, where clouds and rain were more prevalent. In the eastern part of the region temperatures were above normal. Average daily temperatures ranged from 2°F (1.1°C) below normal in western Missouri to 3°F (1.7°C) above normal in central Ohio. Temperatures across the upper Midwest were 1°F (0.6°C) to 2°F (1.1°C) above normal.
  
  
• Heavy rain fell in the central Midwest during the first half of September largely as a result of Hurricanes Gustav and Ike. Most locations from Missouri through Illinois into southern Michigan received two to three times normal September rainfall the first two weeks of the month. A number of locations set monthly records for precipitation. Dry weather settled in the last half of the month, and rain was generally limited to scattered showers and thunderstorms associated with frontal passages. While the central Midwest experienced soaking rains, the northwestern and southeastern portions of the Midwest were very dry. Precipitation in Kentucky and southern Ohio was only 20 percent to 40 percent of normal, and precipitation across central Wisconsin was less than 50 percent of normal. By the end of September the U.S. Drought Monitor depicted severe drought in parts on Kentucky, Minnesota, and Wisconsin.
  
  
• Heavy rain along a stalled front on September 11-12 produced widespread flooding in southern Iowa, northern Illinois, northern Indiana, and southwestern Michigan prior to the rain associated directly with the remnants of Hurricane Ike. The additional rain with Ike made a bad situation worse. The Chicago suburban community of Wheaton received 10.51 inches (267 mm)of rain between September 12 and 14. O'Hare International Airport received 6.64 inches (169 mm) of rainfall on September 13, setting a new record for the highest calendar day rainfall total. Numerous roads throughout northeastern Illinois were closed by flooding. Creeks and rivers rapidly rose and overflowed their banks, and record flood stages were reached on many area rivers. Northwest Indiana was especially hard hit by flooding rains. Portage, IN received 11.46 inches (291 mm) of rain between September 12 and 14, while South Bend received 10.94 inches (278 mm) of rain in the same period. A CoCoRaHS station in La Porte, IN recorded 13.06 inches (332 mm) of rain. Record flooding occurred on many rivers in northwest Indiana, and a 40-mile stretch of Interstate 65 in northern Indiana was closed for two days due to flooding. Six fatalities resulted from the flooding, two each in Missouri, Illinois, and Indiana. As the remnants of Ike accelerated through the Midwest on September 14, the strong pressure gradient between the low and high pressure over the eastern United States produced a band of strong, damaging winds along and south of the low's path. Winds gusted to between 50 and 60 mph, with a gust to 75 mph reported at Port Columbus International Airport in Franklin County, OH, and an unofficial gust of 84 mph was recorded in West Chester, OH. The winds caused massive power outages across Ohio, Kentucky, and Indiana. At one time an estimated 1.92 million customers in Ohio and 1.2 million customers in Kentucky were without power. The winds also caused major crop damage, and at least eight fatalities were attributed to trees and limbs toppled by the wind.
  

• Similar to August, average temperatures for September 2008 were within two degrees of normal over the vast majority of the region including Puerto Rico. Several small areas, including northwest Georgia and northern Virginia, recorded warmer temperatures than normal, including Washington D.C., which registered its 11th warmest September on record. There were 54 record highs and 50 record low temperatures during the month. Most of the record highs occurred near the middle of the month as the Bermuda High briefly extended westward across the region. Most of the record lows occurred towards the end of the month as a strong high pressure centered northeast of the region advected relatively cool air into the region.
  
  
• Precipitation during September 2008 was most excessive across Puerto Rico. A weak, broad area of low pressure stalled across the region between September 21st and 25th before moving northward and developing into Tropical Storm Kyle. The south slopes of Puerto Rico were especially hard hit with Guayama receiving 20 inches (508 mm) on September 22. Guayama, in fact, recorded a total of 36.62 inches (930mm) for the month, breaking a 97-year record for the wettest month. Three tropical storms and a strong extratropical system contributed to heavy precipitation totals across portions of the region during the month. On September 1st, the outer bands of Hurricane Gustav provided rainfall across the western panhandle of Florida and southern Alabama. Early on September 6, Tropical Storm Hanna made landfall on the North and South Carolina border and moved rapidly north-northeastward to eastern Virginia producing heavy rainfall immediately west of its path, including 8.73 inches (222 mm) in Marion, South Carolina, 6.68 inches (170 mm) in Southern Pines, North Carolina, and 8.35 inches (212 mm) in Woodbridge, Virginia. On September 9th and 10th, the northern and eastern outer bands of Hurricane Ike provided heavy rainfall over the Keys and southwestern Florida. Fort Myers recorded 3.83 inches (97 mm) during this period. On September 25th and 26th, a strong extratropical system made landfall near the North and South Carolina border and dissipated as it moved slowly westward across the Carolinas. Broad rainfall bands circulating around this system produced heavy rainfall totals of 3-6 inches (76-152 mm) across portions of North Carolina and Virginia. The heavy rainfall accompanying Tropical Storm Hanna contributed to prodigious monthly precipitation totals (greater than 150 percent of normal) across a narrow swath stretching across northeastern South Carolina, east-central North Carolina and eastern Virginia. Norfolk, Virginia and Raleigh-Durham, North Carolina recorded nearly 9.5 inches (241 mm) of rain during the month making it the 7th and 4th wettest Septembers on record, respectively. Interestingly, Norfolk's heavy rainfall came on the heels of the 2nd driest August on record. Much of the remainder of the region received less precipitation than normal for the month. Most of Georgia, Alabama, extreme western North Carolina, and northern Florida received less than half of the normal monthly precipitation. Macon, Georgia and Birmingham, Alabama received only 0.39 inch and 0.40 inch (10 mm) precipitation, respectively, during the month.
  
  
• The meager precipitation totals across much of the region contributed to an expansion of drought conditions. Exceptional drought continued to plague northwestern South Carolina, while the area of extreme drought expanded across a broader region of western NC and northern Georgia. Additionally the region of severe drought expanded to include much of the remainder of Georgia. The highest recorded winds during the month were associated with Tropical Storm Hanna on September 6th. Wind gusts of 72 and 52 mph were recorded at Wrightsville Beach and Goldsboro, North Carolina, respectively. Key West, Florida recorded a wind gust of 60 mph in association with the outer bands of Hurricane Ike on September 9th.
  

• Temperatures were cool for most of the region with monthly average temperature departures ranging anywhere from 2-4°F (1.1-2.2°C) below normal. Examples of the cool temperatures include Iola, KS and Toronto Lake, KS. The station known as Iola 1W had an average temperature of 66.0°F (18.9°C), which was the 6th coolest September on record. Toronto Lake also had their 6th coolest September on record with an average temperature of 66.2°F (19.0°C). The highest temperature in the region was 101°F (38.3°C) and occurred on September 1st at the station known as Cottonwood 2 E, SD. This was the 6th highest temperature on record for that day. The lowest temperature in the region, 13°F (-10.7°C), occurred on September 2nd at Pinedale, WY and was the 6th lowest temperature on record for that day.
  
  
• September 2008 was dry for southern Colorado, the western Dakotas, and portions of Wyoming and Nebraska. Drought conditions continued in western North Dakota, western Wyoming, and places along the Colorado-Kansas border. Elsewhere, the lack of precipitation in South Dakota helped contribute to the development of moderate drought conditions. Rain in eastern North Dakota and eastern Nebraska helped alleviate drought conditions, with many locations receiving 150-300 percent of normal precipitation. One exceptionally wet spot was Wichita, KS where they experienced the wettest September on record with 12.96 inches (329.2 mm) of precipitation, or 438 percent of normal. Additionally, a new 24-hour rainfall record was set on September 12th for the Wichita Mid-Continent Airport where 10.31 inches (261.9 mm) of rain fell. This crushed the old record of 1.75 inches (44.5 mm) set back in 1961.
  
  
• The remnants of tropical system Lowell interacted with a stationary boundary to bring record rainfall to the Wichita, KS area. The monthly record for Wichita for September was already broken by the 12th of the month and ultimately, this September was the 4th wettest month on record. The torrential rainfall caused street flooding and many creeks in the area overflowed. Over 100 cars were stranded and many homes were flooded as well.
  

• In the month of September, average temperatures in the Southern Region were quite variable. In Texas and Oklahoma, temperatures ranged from normal to below normal. With the exception of the Texas gulf coast, and the western panhandle of Oklahoma, temperatures averaged 2-5°F (1-2.5°C) below the monthly norm. Similar departures in temperature were also observed in southwestern Arkansas and northwestern Louisiana. The remainder of Arkansas was generally within just 2°F (1°C) of normal. This was also the case through out Mississippi and the extreme southwestern tip of Tennessee. Generally speaking, temperatures in Tennessee were approximately 2-4°F (1-2°C) above the monthly mean.
  
  
• Precipitation for the month of September was highly variable with locations receiving either copious amounts of precipitation or little to no precipitation at all. In Tennessee for example, most locations received less than 50 percent of the monthly normal. In fact, many locations in the central and northwestern parts of the state remained below the 25 percent of normal mark. This was also observed in the Oklahoma and Texas panhandles, in south central Oklahoma and in south central Texas. Precipitation totals elsewhere were generally well above normal, in part to the contributions from Hurricanes Gustav and Ike. The track of Gustav brought anomalously high precipitation totals extending from southern Louisiana and Mississippi to the northern Arkansas border. Along this stretch, precipitation totals varied from 150-300 percent of normal, with the highest values being observed in the northeastern corner of Louisiana. Similar totals were also observed in a line from southwestern Texas to central Oklahoma.
  
  
• Drought conditions in the Southern Region changed little from last month. Drought conditions were present in central Texas, the panhandle of Oklahoma, and in most of Tennessee. In central Texas, approximately a dozen counties were experiencing extreme drought conditions. To the west of this, an area of similar size was in severe drought. As was the case last month, severe drought was also present in the panhandle of Oklahoma. In Tennessee, drought conditions remained firmly in place, with almost 80 percent of the state experiencing moderate drought or worse, with the majority (58.8 percent) of the state in severe drought or worse. The most critically affected areas of the state continued to reside in the eastern counties, where approximately a dozen counties were observing extreme drought conditions.
  
  

• Temperatures were near normal in the West with slightly below readings in the intermountain region and the northwest to slightly above normal in the southwest.
  
  
• Precipitation was generally below to near normal throughout the region except for Montana and Wyoming, who measured slightly above normal rainfall. Colorado Springs had a very local and heavy event on the 11th when 4.29 inches (109 mm) fell at the airport. This not only exceeded their greatest 24-hour total on record, but their greatest September total as well.
  
  
• September was not an active month with very little storm activity to report. The first of the month saw snow fall in the upper elevations of western Montana with up to 6 inches (15.2 cm) in some mountain locations. Also of note was a flash flood in a Utah slot canyon in the Grand Staircase-Escalante National Monument on the 10th that killed 2 and injured 2.
  

• Much of Alaska experienced above average temperatures for September with a average temperature of 1.1°F (0.6°C) above the 1971-2000 average. The average maximum temperature in Fairbanks was 56.0°F ( 13.3°C) and the average minimum temperature was 37.0°F (2.8°C). The average monthly temperature of 46.6°F (8.1°C) was 2.1°F (1.2°C) above normal. The panhandle saw cooler than normal daytime highs and warmer than normal nighttime lows. The daily high temperatures ranged from 1.7°F (0.9°C) below normal in the northern panhandle to 3.0°F (1.7°C) below normal in the central outer coast. Nome saw eight days with temperatures 60.0°F (15.6°C) or above. This topped the previous high of 5 days back in 1996. For the month of September, Nome registered a monthly average temperature of 52.8°F (11.6°C) which was 2.3°F (1.3°C) above normal. The average monthly temperature for Barrow in September was 34.0°F (1.1°C) which was 2.8 °F (1.6°C) above normal, tying it with 1973's mark of the 18th warmest on record.
  
  
• The state of Alaska posted monthly precipitation totals that were near normal for the month of September. Precipitation across the panhandle was above normal for the month of September with exception to the southern locations. Northern locations saw only their second month of significantly above normal precipitation this year. The central part of the panhandle saw even greater above normal precipitation amounts. In Fairbanks, the airport recorded 0.64 inch (16 mm) of precipitation. The total snowfall of 1.8 inches (30 mm) is the most snow during the month of September in four years. It was the driest September ever in Nome, where .06 inch (2 mm) of precipitation was recorded. The previous record was 0.39 inch (10 mm) set back in 1968 and 1943.