NOAA's National Centers for Environmental Information
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Temperature
Globally averaged temperatures were anomalously warm in January 2001. A return to near-record land temperatures and above average ocean temperatures led to a combined land and ocean temperature that was 0.52C (0.94F) above the 1880-2000 long-term mean (0.41C [0.74F] warmer than the 1961-1990 base period), the third warmest January in the 122 year time series. Since 1978, this was the 24th January in a row with above average global temperatures. After weakening in mid-2000, La Nina conditions have been strengthening in recent months, with subsurface anomalies as great as -3C (-5.4F) in the equatorial waters of the eastern Pacific. Nonetheless, globally averaged sea surface temperatures were 0.35C (0.63F) above average, the fifth warmest January on record. Land surface temperatures, in contrast to January 2000, once again averaged near all-time highs, 0.91C (1.64F) above the 1880-2000 average. Temperatures remained near record levels in the northern and southern hemisphere extratropics, while the continuation of La Nina conditions contributed to temperatures in the Tropics that were closer to the long-term average.
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The adjacent map shows large areas of above-average temperatures (based on a 1961-1990 base period) in North America and Europe. A westerly flow of milder Pacific air covered much of Canada and the U.S. northern Plains resulting in temperatures from 5C (9F) to 10C (18F) above normal in January. Above normal temperatures also stretched from Western Europe to the Ural Mountains with temperatures more than 5C (9F) above the 1961-1990 average in Eastern Europe. |
This contrasted sharply with a large area of below-average temperatures covering much of Central Asia. Temperatures were from 3C to 6C below average throughout much of central and eastern Russia as well as eastern Mongolia and northeast China. Herders in Inner Mongolia continue to deal with temperatures as low as -60F (-51C) and heavy snow that has killed hundreds of thousands of cattle. See NCDC's Climate Watch page for more information on this and other extreme events in January. In the Southern Hemisphere, temperatures were much above average in southeastern Australia and the southern one-third of South America.
Precipitation
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January precipitation anomalies using a base period of 1961-1990 are shown on the adjacent map. Much of the continent of Australia recorded drier than normal conditions in January 2001 with precipitation deficits exceeding 50mm (2 inches) in northern and eastern parts of the continent. Much of Brazil and northern sections of South America were also drier than normal, in contrast to the previous month when rainfall was more than 100mm (4 inches) above normal in many of these same areas. |
| Much of the U.K. was drier than normal, after months of above average precipitation which brought flooding to parts of the country. The only exception was in Wales where heavy rains brought flooding at the beginning of the month. An area of positive precipitation anomalies stretched from Portugal to the Balkans. Precipitation was also above normal in the Far East, some islands of the western Pacific, much of Argentina and the central U.S. A period of below normal precipitation which began more than 2 1/2 years ago in the southern U.S. continued in January. Drier than normal conditions also continued in the U.S. Pacific Northwest with seasonal snowpack less than 50% of normal in many locations. Regional climate highlights for the globe and the U.S. are available. |
References:
Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global
Historical Climatology Network Database. Bull. Amer. Meteorol.
Soc., 78, 2837-2849.