January 2012 was marked by a month of extreme temperatures, particularly across Northern Hemisphere middle and high latitude land areas. The globe experienced its 19th warmest January on record with an average temperature of 54.30°F, which is 0.70°F above the 20th century average. This marks the 323rd consecutive month with a global temperature above the 20th century average. The last month with below average temperatures was February 1985.
Warmer or above normal temperatures was concentrated across most of North America, the northern latitudes of Europe and Asia, southern South America, and most of Australia. Meanwhile, cooler than normal readings were observed across China, Mongolia, Kazakhstan, south central Russia, much of the Middle East, northern India, north Africa, and southwestern Greenland.
The contiguous United States had its fourth warmest January since records began in 1895. For the first January since 2006, none of the contiguous 48 states reported monthly temperatures below the period-of-record average.
The United Kingdom experienced its warmest January since 2008, with the average temperature 1.3°C (2.3°F) above the 1971–2000 average.
According to the Bureau of Meteorology, the average maximum temperature across Australia was 0.43°C (0.77°F) below average, making this the coolest January since 2000 and the 13th coolest since national records began in 1950. Meanwhile, the average January 2012 minimum temperature was near normal, at 0.06°C (0.11°F) above average.
The Arctic Oscillation (AO) climate pattern played a role in temperatures in the Northern Hemisphere during January. The +AO phase during the first half of the month contributed to well-below average monthly temperatures across Alaska and above-average temperatures across the contiguous United States. The negative (-) phase during the second half of the month contributed to warmth in Canada and also to a cold snap that began during the last week in January across Central and Eastern Europe and north Africa.
The growth rate for Arctic sea ice in January was the slowest in the satellite record. The average sea ice extent for the month was 7.5 percent below average, ranking as the fourth smallest January extent since satellite records began in 1979. The extent was 425,000 square miles (1.1 million square kilometers) below average. This marks the 19th consecutive January and 128th consecutive month with below-average Arctic sea ice extent.
Northern Hemisphere snow cover extent during January was slightly above average, with large differences between the North American and Eurasian land areas. Eurasia had its ninth largest snow cover extent in the 46-year period of record, where cold and snowy conditions dominated across central and Eastern Europe, as well as much of China. North America had its third smallest January snow cover extent, where much of the United States and southern Canada were warmer and drier than average, limiting snow cover.
Monsoonal rains brought much above normal rainfall to southwestern and southeastern Australia. Precipitation was also much above average in south Asia, part of eastern Russia, and southwestern Greenland. Meanwhile, drier than average conditions were observed across northern Canada, the north central United States, eastern Brazil, and northern Sweden.
Spain experienced its sixth driest January in the past 50 years. Average rainfall across the country was 21 mm (0.83 inch), which is 70 percent below average for the month.
Conversely, it was the sixth wettest January in Germany since national records began in 1881. Average precipitation was 105.1 mm (4.14 inches), which is 72.8 percent above the monthly average, according to Germany's national meteorological agency.
Wetness was prevalent on both the east and west coasts of Australia. The state of Western Australia had its 11th wettest January on record. In eastern Australia, New South Wales experienced its highest January rainfall since 1996.
Comments