Climate of 2009

April in Historical Perspective

National Climatic Data Center, 20 May 2009

Contents Of This Report:
Selected Global Significant Events for April 2009

2008 Annual Report is available here.

Major Highlights

NOAA: April Temperature Slightly Cooler Than Average for the U.S.
Fifth Warmest April for Globe

The April 2009 temperature for the contiguous United States was below the long-term average, based on records going back to 1895, according to an analysis by NOAA's National Climatic Data Center in Asheville, N.C.

The average April temperature of 51.2 degrees F was 0.8 degrees F below the 20th Century average. Precipitation across the contiguous United States in April averaged 2.62 inches, which is 0.19 inch above the 1901-2000 average.

The combined average global land and ocean surface temperatures for April 2009 ranked fifth warmest since worldwide records began in 1880, according to an analysis by NOAA's National Climatic Data Center in Asheville, N.C.

U.S. Temperature Highlights

April temperatures were near normal across much of the United States. On a regional scale, only the Northeast (above-normal) and the West North Central (below-normal) deviated significantly from the norm.

New Hampshire observed its eighth warmest April, based on data going back to 1895. Unlike much of the Northeast, the Midwest experienced a cooler-than-normal month. From North Dakota southward to Oklahoma, Missouri, Louisiana, Alabama and Georgia, temperature averages were below normal.

For the year-to-date period, only two states, North Dakota and Washington, have experienced cooler-than-normal average temperatures. In contrast, much of the South and Southwest regions were above-normal. New Mexico had its ninth warmest such period on record.

Based on NOAA's Residential Energy Demand Temperature Index, the contiguous U.S. temperature-related energy demand was 2.3 percent below average in April.

Global Temperature Highlights

April's combined global land and ocean surface temperature was 1.06 degree F above the 20th century average of 56.7 degrees F. The most significant warmth occurred in northern and northeastern Asia, Europe, and much of the planet's southern oceans.

The global combined land and ocean surface temperature of 55.8 degrees F is tied with 2003 for the sixth-warmest January-through-April period on record. This value is 0.97 degree F above the 20th century average.

The global land surface temperature for April was 1.80 degrees F degrees above the 20th century average of 46.5 degrees F degrees.

U.S. Precipitation Highlights

Above-normal precipitation fell across parts of the Central and South regions, while the West and Northwest regions experienced below-normal precipitation averages.

For the contiguous United States as a whole, precipitation was above normal. States that experienced April precipitation among the ten wettest of the 115-year record were Georgia (5th), Kansas (9th), Michigan (9th), and Illinois (10th). Only seven states averaged drier-than-normal for April.

For the year to date, the Northeast experienced its fourth driest January-through-April period on record and it was the twelfth driest such periods for the contiguous U.S.

By the end of April, moderate-to-exceptional drought covered 18 percent of the contiguous United States, based on the U.S. Drought Monitor. This is seven percentage points less than the end of March. Severe or extreme drought conditions continued in parts of California, Florida, Hawai'i, Nevada, Wisconsin, the southern Appalachians, and the southern Plains, with exceptional drought in southern Texas.

About 21 percent of the contiguous United States had moderately-to-extremely wet conditions at the end of April, according to the Palmer Index (a well-known index that measures both drought intensity and wet spell intensity).

Other U.S. Highlights

International Falls, Minnesota recorded 125 inches of snow so far this winter season, breaking the previous record of 116 inches set in the 1995-1996 winter season. Another seasonal snowfall record was broken in Spokane, Washington where 97.7 inches of snowfall broke the old record of 93.5 inches set in 1915-1916.

About 8 percent of the contiguous U.S. was covered by snow at end of April, according to an analysis by the National Operational Hydrologic Remote Sensing Center. Snow coverage during the month peaked at 30.2% on April 6th, after a late-season winter storm hit the Midwest and Plains.

Convective activity during Easter weekend spawned tornadoes across the southern U.S. killing five people. The 263 preliminary (not yet confirmed) tornadoes reported in April was above the 3-year average of 200 confirmed tornadoes.

According to data collected by the National Interagency Fire Center, approximately 485,373 acres burned and 10,009 new wildfires were reported across the nation during April 2009. Each number ranks second highest during this decade. For 2009 to-date, approximately 1,064,711 acres have been burned in 32,063 fires throughout the U.S. These values rank third and second highest, respectively.

Other Global Highlights

Arctic sea ice coverage of 5.6 million square miles was the tenth-lowest April extent since satellite records began in 1979, according to NOAA's National Snow and Ice Data Center. This value is 2.8 percent below the 1979-2000 average. In contrast, the April Southern Hemisphere sea ice extent of 3.2 million square miles was 13.5 percent above the 1979-2000 average. April is early in the melt season for Arctic sea ice, and early in the growth season for Antarctic sea ice.

Based on NOAA satellite observations, April snow cover extent was below the 1967-2009 average for the Northern Hemisphere. This marked the hemisphere's sixth consecutive April with below-average snow cover extent. Warmer-than-normal conditions over Eurasia contributed to that region's fourth-smallest April snow cover extent during the period. North American snow cover extent was slightly above average during the month.

Report Index

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to the top Global Hazards and Significant Events

to the top National and Regional Overview

to the top United States Drought