State of the Climate
National Oceanic and Atmospheric Administration
National Climatic Data Center
Use the form below to access monthly reports.
Selected National Highlights for September 2009
- Temperature Highlights - September
- The average
September temperature of 66.4°F was 1.0°F above the 20th Century average and ranked as the 32nd warmest based on preliminary data.
- On a
regional level, the
West experienced its warmest September on record. The
Northwest and
West North Central experienced their sixth and eleventh warmest such periods.
-
Nevada
experienced its warmest September of the 115-year record.
California's
average temperature tied with 1984 as the warmest on record. In addition, six other states observed September temperatures among their ten warmest:
Montana (3rd warmest),
North Dakota (3rd),
Idaho (4th),
Utah (5th),
Minnesota (6th), and
Oregon (8th).
- In the South, a combination a slow-moving storm system during the beginning of the month and two surface cold fronts during the last week resulted in much below normal temperature averages in
Kansas (10th coolest) and
Oklahoma (11thcoolest).
- Several divisions in the northern tier states along the Canadian border as well Nevada and Montana averaged record high temperatures during the month. In North Dakota, three contiguous divisions were record warmest in September (Division
1,
2, and
3). Divisions
1 and
2 in Minnesota also experienced record warm temperature averages. Other record warm divisions were in Nevada (Division
1 and
3) and Montana (Division
2).
- For the
year-to-date (January–September) period, the contiguous U.S. ranked 29thwarmest.
New Mexico and
Arizona recorded their tenth- and eleventh-warmest such periods on record, respectively.
- Precipitation Highlights - September
- Precipitation was exactly the
long-term average for the contiguous U.S. as a whole, but
regional amounts varied widely. The
South experienced its sixth-wettest September, which was countered by the sixth-driest such period in the
East North Central region.
- An upper level storm system stalled over the Deep South during the month, bringing copious rains to the region. Statewide-averaged rainfall was among the ten wettest for four southern states (
Arkansas, 2nd wettest; 
Tennessee (5th), 
Mississippi (6th), and 
Alabama (6th)).
- Despite record and flood-producing rains in northern Georgia, drier conditions near the coast kept the state's overall average out of the top ten wettest. However, several divisions in the Southeast averaged a record amount of precipitation averages for the month. In Georgia,
Division 1 averaged 11.39 inches, breaking the old record of 9.56 inches set back in 1957.
Division 2 averaged 13.07 inches, surpassing the previous record of 12.57 inches recorded just five years prior. In Alabama,
Division 3 averaged 10.91 inches of precipitation, breaking the previous record of 10.62 inches set in 1906.
Maine and
Wisconsin each experienced their fourth driest September and both
New Hampshire and
Michigan had their seventh driest such periods. - Persistent wetness in
Arkansas resulted in the state's 10th wettest year-to-date period, while the lack of monsoon moisture this summer helped hold
Arizona to its fifth driest year-to-date period in 115-years of records.
- By the end of September, moderate-to-exceptional drought covered 15 percent of the contiguous United States, based on the U.S. Drought Monitor. Drought intensified in the Upper Midwest and eastern Carolinas, while remaining entrenched in much of the West. Drought conditions remained severe in south Texas, despite some improvement.
- About 27 percent of the contiguous United States had moderately-to-extremely wet conditions at the end of September, according to the Palmer Index (a well-known index that measures both drought intensity and wet spell intensity). Additional drought information can be found on the State of the Climate - Drought page.
- Other Items of Note
- Severe weather was limited in September. In the contiguous U.S.; only 10 preliminary tornado reports were recorded by the Storm Prediction Center. Even if all September reports are confirmed, it will represent only 8 percent of the three-year average of 82. With the exception of June, U.S. tornadic activity was well below average to date during 2009.
- During mid-month, a persistent low pressure system in the Deep South and a high pressure system off the eastern seaboard channeled heavy rains into the western Carolinas and the northern half of Georgia. The rains and already-saturated grounds combined to create runoff that overwhelmed many streams and rivers. Major to record flooding occurred across the Atlanta metropolitan area. Eight-day precipitation totals as high as 24 inches were reported in the region.
- During September, 5,535 fires burned approximately 378,523 acres, each of which was below the 2000–2009 average for the month. The acreage lost to wildfire was roughly half of the 2000–2009 average. For the year to date (January–September), 70,217 fires was slightly above the 10-year average, while acreage burned was slightly less than average.
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Selected Global Highlights for September 2009
- The combined global land and ocean surface temperature for September 2009 was 0.62°C (1.12°F) above the 20th Century average of 15.0°C (59.0°F). This was the second warmest September on record, behind 2005, and the 33rd consecutive September with a global temperature above the 20th Century average. The last below-average September occurred in 1976.
- The global land surface temperature for September 2009 was 0.97°C (1.75°F) above the 20th Century average of 12.0°C (53.6°F), and ranked as the second warmest September on record, also behind 2005.
- The worldwide ocean temperature tied with 2004 as the fifth warmest September on record, 0.50°C (0.90°F) above the 20th Century average of 16.2°C (61.1°F). Warmer-than-average sea surface temperatures were widespread, particularly in lower latitudes. The near-Antarctic southern ocean and the Gulf of Alaska featured notable cooler-than-average temperatures.
- For the year to date, the global combined land and ocean surface temperature of 14.7°C (58.5°F) was the sixth-warmest January-through-September period on record. This value is 0.55°C (0.99°F) above the 20th Century average.
- A weak El Niño persisted across the equatorial Pacific Ocean during September. Sea surface temperature observations in the equatorial Pacific Ocean during the month remained above average. According to NOAA's Climate Prediction Center, El Niño is expected to strengthen and last through the Northern Hemisphere winter of 2009-2010.
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Overview
The State of the Climate Report is a collection of monthly summaries recapping climate-related occurrences on both a global and national scale. The report is comprised of the following sections:
- Global
- Global Analysis — a summary of global temperatures, precipitation, snow cover and sea ice extent, placing the data into a historical perspective
- Global Hazards — a summary outlining weather-related hazards and disasters around the world
- El Niño/Southern Oscillation Analysis — a summary of atmospheric and oceanic conditions related to ENSO
- National
- National Overview — a summary of national and regional temperature and precipitation, placing the data into a historical perspective
- Drought — a summary of drought in the U.S.
- U.S. Wildfire — a summary of weather and climate conditions related to wildland fires in the U.S.
- Hurricanes & Tropical Storms — a summary of hurricanes and tropical storms that affect the U.S. and its territories
- Snow & Ice — a summary of snow and ice in the U.S.
- Tornadoes — a summary of tornadic activity in the U.S.
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Questions?
For all climate questions, please contact the National Climatic Data Center's Climate Services and Monitoring Division:
Climate Services and Monitoring Division
NOAA/National Climatic Data center
151 Patton Avenue
Asheville, NC 28801-5001
fax: +1-828-271-4876
phone: +1-828-271-4800
email: ncdc.info@ncdc.noaa.gov
To request climate data, please E-mail:ncdc.orders@ncdc.noaa.gov
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