Dec. 15, 2005 — After a record-breaking hurricane season, blistering heat waves, lingering drought and a crippling Northeast blizzard, 2005 is ending as a warm year in the United States. It will come close to the all-time high global annual average temperature, based on preliminary data gathered by scientists at the NOAA National Climatic Data Center in Asheville, N.C. (Click on NOAA image for larger view of USA significant weather and climate events for 2005. Please credit "NOAA.")
Warmer-than-average 2005 for U.S.
NOAA scientists report that the 2005 annual average temperature for the contiguous United States (based on preliminary data) will likely be 1.0 degrees F (0.6 degrees C) above the 1895-2004 mean, which will make 2005 one of the 20 warmest years on record for the country. Mean temperatures through the end of November were warmer than average in all but three states. No state was cooler than average. A July heat wave pushed temperatures soaring beyond 100 degrees, and broke more than 200 daily records established in six western states. A new record of seven consecutive days at — or above — 125 degrees F was established at Death Valley, Calif. The heat wave spread across the country during late July, scorching the East and prompted record electricity usage in New England and New York.
Drought, Rainfall and Snow
The 2004-2005 winter was a season of contrasts for the West, with excessive rainfall in the Southwest and severe drought in the Northwest. A parade of winter Pacific storms triggered severe flooding and devastating landslides in southern California and brought the second-wettest winter on record to the Southwest region. Record and near-record snowpack levels, which were widespread across the Southwest by early spring, eased drought in a region where it had persisted for five years. Meanwhile, drought conditions worsened in the Pacific Northwest and northern Rockies in early 2005 and snowpack in much of the region was at record low levels at the end of winter. However, above average precipitation in subsequent months led to improving drought conditions in much of the region. (Click on NOAA image for larger view of annual 2005 state rankings by precipitation. Please credit "NOAA.")
During spring, the drought focus shifted to the Midwest and southern Plains. Severe dryness persisted across parts of northern Illinois, with Chicago and Rockford recording their driest March-November on record. Drought disasters were declared in all or parts of Arkansas, Illinois, Iowa, Kansas, Missouri, Texas and Wisconsin. Drier-than-average conditions contributed to an active wildfire season that burned more than 8.5 million acres in 2005 — 4.5 million acres consumed in Alaska alone, based on preliminary data from the National Interagency Fire Center. This exceeds the old record set in 2000 for acreage burned in a wildfire season for the United States as a whole. At the end of November, 18 percent of the contiguous United States was in moderate-to-extreme drought based on a widely used measure of drought (the Palmer Drought Index) in contrast to six percent at the end of November last year. (Click on NOAA image for larger view of annual 2005 state rankings by temperature. Please credit "NOAA.")
Record precipitation fell in the Northeast during the fall with three storm systems affecting the region in October. Nine states in the Northeast had their wettest October since 1895, and the October snowfall record on Mount Washington was shattered when 78.9 inches of snow fell during the month. Another notable snow storm in 2005 was the ‘Blizzard of 2005,’ which brought more than two feet of snow across much of southern New England in late January. This storm ranked as the seventh most extreme snow event in the Northeast as measured by a newly developed Northeast Snowfall Impact Scale (NESIS) index and contributed to the snowiest January on record in Boston.
Tropical Cyclones and Hurricanes
The 2005 Atlantic hurricane season set several records. There were 26 named storms (storms with sustained winds of at least 39 miles per hour). In addition, there were an unprecedented 14 hurricanes, of which seven were major hurricanes (Category 3 or better on the Saffir-Simpson Scale). Three category 5 storms (sustained winds of 156 miles per hour or more) formed in the Atlantic Basin for the first time in a single season (Katrina, Rita and Wilma). Four major hurricanes and three tropical storms made landfall in the U.S., with an eighth storm (Ophelia) brushing the North Carolina coast. Tropical cyclone activity was near to below average in the Eastern Pacific and Western North Pacific basins through early December.
The global annual temperature for combined land and ocean surfaces is expected to be very close to the record global temperature that was established in 1998 under the influence of an extremely strong El Niño episode. There has been no such El Niño event in 2005, but rather, unusual warmth across large parts of the globe throughout the year. NOAA is in the process of transitioning to an improved global temperature analysis system. The data analysis system used by NOAA for global temperature analyses over the past eight years indicates that 2005 would likely be the second-warmest year on record (1.06 degrees F; 0.59 degrees C above the 1880-2004 mean), marginally lower than 1998. (Click on NOAA image for larger view of January - December global surface mean temperature anomalies from 1880 to 2005. Please credit "NOAA.")
The largest temperature anomalies were widespread throughout high latitude regions of the Northern Hemisphere and included much of Russia, Scandinavia, Canada and Alaska. During the past century, global surface temperatures have increased at a rate near 1.1 degrees F/Century (0.6 degrees C/Century), but the rate of temperature increase has been three times larger since 1976, with some of the largest temperature increases occurring in the high latitudes.
Reflecting the global warmth in 2005, a new record was established in September for the lowest Arctic sea ice extent since satellite monitoring began in the late 1970s, according to the National Snow and Ice Data Center. This is part of a continuing trend in end-of-summer Arctic sea ice extent reductions of approximately eight percent per decade since 1979. (Click on NOAA image for larger view of global significant climate anomalies and events in 2005. Click here for high resolution version. Please credit "NOAA.")
The year began with the continuation of a weak El Niño episode that developed in late 2004, but sea surface temperatures in the central and east-central equatorial Pacific decreased early in the year and the episode ended by late February. Few impacts from the weak El Niño occurred worldwide, and neutral conditions persisted for the remainder of the year.
Significant weather and climate events for the globe included: severe drought in parts of southern Africa and the Greater Horn of Africa, extreme monsoon-related rainfall in western India including a 24-hour rainfall total of 37.1 inches in Mumbai, the worst drought in decades in the Amazon River basin, severe drought in large parts of western Europe, and a record warm year in Australia.