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NOAA reports Nov. 2001 - Jan. 2002 was the warmest such period on record.February 21, 2002 — The contiguous United States experienced record warmth during the November 2001 through January 2002 three-month period, scientists at NOAA's National Climatic Data Center in Asheville, N.C., said today. The January global temperature was the warmest in the 123-year surface record. Using the world's largest weather database, NOAA scientists calculated conditions for the past three months.

"Unusual warmth persisted across a large part of the contiguous United States during the past three months resulting in the warmest November through January since national records began in 1895," said Jay Lawrimore, chief of NOAA's Climate Monitoring Branch at the Asheville center. The preliminary nationally averaged temperature was 39.94 F (4.41 C), which was 4.3 F (2.4 C) above the 1895-2001 long-term mean. The previous record for the same three-month period was established in 1999-2000. Since 1976 the nationally averaged November-January temperature has risen at a rate of 1.2 F (0.7 C) per decade.

During the most recent three-month period, much above-average warmth stretched from as far west as Montana and Oklahoma to the East Coast. Minnesota, Wisconsin, Iowa, Massachusetts and Vermont had their warmest November to January, and as many as 18 states from the Plains to the Northeast recorded their second warmest November-January.

In that region numerous daily high-temperature records were established and the warmth coincided with below-normal snowfall. A lack of snow cover contributed to short-term drought conditions in the northern Plains. Absence of snow has affected many winter festivals in the northern United States.

The three-month Residential Energy Demand Temperature Index (November-January) was the lowest on record, reflecting reduced energy demand due to the anomalously warm temperatures. This index, which has values from zero to 100, measures year-to-year fluctuations in residential energy demand that result from variations in temperature in the contiguous United States, especially those that occur in the most heavily populated areas. An index value of 100, the greatest temperature-related energy demand for the November-January period, occurred in 1976-77, while the past three months registered an index value of zero.

Although precipitation was near normal nationwide from November to January, an area of below normal precipitation stretched from Florida to Maine, worsening drought conditions along the East Coast. Connecticut and Maine experienced their driest November-January on record and nine other states (New Hampshire, Massachusetts, Rhode Island, New Jersey, Maryland, Delaware, West Virginia, Virginia and South Carolina) were much drier than normal.

At the end of January, moderate to severe drought conditions were widespread from southern Georgia to Maine. Conservation was encouraged in New York City as reservoirs were filled to less than half of capacity. Drought continued in much of the Inter-Mountain West while abundant rain and snowfall along the West Coast alleviated drought in much of Washington, Oregon and Northern California. Severe to extreme drought covered approximately 18 percent of the contiguous United States at the end of January.

January 2002 ranked as the seventh warmest January in the 1895 to present record. The preliminary nationally averaged temperature was 35.40 F (1.89 C), which was 4.5 F (2.5 C) above the long-term mean. Above-average warmth occurred in all but eight of the 48 contiguous states, with near-normal temperatures occurring in Florida, Alabama, Louisiana, Colorado, Utah, Nevada, Oregon and California. The nationally averaged precipitation total was near-normal with the most anomalously dry conditions in the Northern Plains and Southwest. Temperatures in Alaska were 11.21 F (6.23 C) above the 1961-1990 average in January, the ninth warmest January on record.

Anomalous warmth covered most land areas of the globe in January, with monthly mean temperatures more than 7 F (4 C) above average throughout large parts of North America and central Asia. The widespread nature, persistence and magnitude of the anomalies in the Northern Hemisphere contributed to an average land surface anomaly that was 2.43 F (1.35 C) above the 1880-2001 long-term mean (based on preliminary data), more than 0.6 F (0.3 C) greater than the previous record warm January.

Warming in the equatorial waters of the central and eastern Pacific occurred in January, indicative of a likely transition from neutral to El Niño conditions. This contributed to the third warmest January for global sea surface temperatures, 0.74 F (0.41 C) above average. The warmest January occurred in 1998 during the most recent El Niño episode.

The combination of record warm land temperatures and near-record sea surface temperatures led to the warmest January on record for both land and ocean surfaces combined, which was 1.24 F (0.69 C) above average and 0.09 F (0.05 C) warmer than January 1998.

Relevant Web Sites
Climate of 2002—January in Historical Perspective

NOAA's National Climatic Data Center

NOAA's Climate Monitoring Branch

NOAA Predicts Sea Surface Temperatures Will Rise in Eastern Tropical Pacific; Forecasters' Confidence Increases That El Niño Will Develop

Media Contact:
Patricia Viets, NOAA, (301) 457-5005