NOAA News || NOAA Home Page || Previous Story: April 18, 2000


Global Warming - View of the EarthMay 19, 2000 — The four-month period of January through April this year was the warmest January-April period on record in the United States in 106 years of record keeping, according to statistics calculated by NOAA's scientists working from the world's largest statistical weather database. NOAA's National Climatic Data Center in Asheville, NC, holds data that spans through the entire 106 years of record keeping. (Note: the graphic on the left shows projected warming 150 years into the future.)

The preliminary data indicate that nearly 70 percent of the country was much warmer than normal, while less than one percent of the country was much cooler than normal. The persistent warmth of the past eleven months has resulted in record warm ranks for several combinations of months ending in April 2000. These include each of the nine periods from February-April 2000, January-April 2000, back to June 1999-April 2000.

The temperature value, at 44.3 degrees Fahrenheit, was .3 degrees over the second warmest January-April, which occurred in 1990.

Nevada had its second warmest April; Arizona its third warmest; New Mexico and Utah their sixth warmest.


Based upon preliminary precipitation data, January-April 2000 ranked near the long-term mean. About eight percent of the country was much wetter than normal, while about three percent of the country was much drier than normal.

It was the driest April on record for Missouri. Conversely, it was the sixth wettest April on record for Vermont and the seventh wettest April for New York.

Global Data:

Land and ocean temperatures continued to average well-above the 1880-1999 long-term mean in April. The average temperature anomaly for both land and ocean surfaces was 0.51 degrees Celsius, slightly cooler than the record warm temperatures recorded during the 1998 El Niño episode. Sea surface temperatures averaged 0.35 degrees Celsius above the long-term mean, the sixth warmest April since 1880. As in recent months, the much warmer than average global temperatures were largely due to a continuation of the extremely warm conditions observed over Northern Hemisphere land surfaces. The global land temperature anomaly was 1.01 degrees Celsius in April, second only to the 1.27 degrees Celsius anomaly recorded in 1998.

The warm Northern Hemisphere temperatures reported through surface-based observations are consistent with satellite observations of lower tropospheric temperatures (from the surface to eight kilometers above the earth's surface). Scientists from the Global Hydrology and Climate Center at the University of Alabama in Huntsville report that although April global temperatures for the lower troposphere were near-normal (-0.01 degrees Celsius below the 1979-1998 average), temperatures in the Northern Hemisphere were much warmer than the 20-year average. The Northern Hemisphere temperature was +0.19 degrees Celsius above average, while temperatures in the Southern Hemisphere were -0.21C cooler than the April average. Temperatures were particularly warm in the Northern Extratropics (north of 20N), where the average April temperature was +0.52 degrees Celsius above average, the 3rd warmest April on record.

The most recent statistics for the United States and the globe are online at:
Climate of 2000 — April in Historical Perspective

NOAA's National Climatic Data Center, Asheville, North Carolina

All About Climate

NOAA's El Niño Page

Media Contacts:
Patricia Viets, NOAA Satellite Operations, (301) 457-5005.