October 2012: Earth's 5th warmest October on record

October 2012 was the globe's 5th warmest October on record, said National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC) today. NASA rated October 2012 the 2nd warmest October on record. Global temperature records begin in 1880. October 2012 global land temperatures were the 8th warmest on record, and global ocean temperatures were the 4th warmest on record. October 2012 was the 332nd consecutive month with global temperatures warmer than the 20th century average. The last time Earth had a below-average October global temperature was in 1976, and the last below-average month of any kind was February 1985. Global satellite-measured temperatures in October 2012 for the lowest 8 km of the atmosphere were 7th or 2nd warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of October 2012 in his October 2012 Global Weather Extremes Summary.


Figure 1. Departure of temperature from average for October 2012, the 5th warmest October for the globe since record keeping began in 1880. Several regions around the globe were much warmer than average, including northeastern and southwestern North America, most of South America, northern Africa, southeastern Europe, southwestern Asia, and far eastern Russia. A heat wave brought record warmth to large areas of Brazil and Bolivia. Record heat was also present in southern India. It was cooler than average in parts of northern Siberia, Mongolia, and northern China along with much of central North America. Western Canada was much cooler than average. Image credit: National Climatic Data Center (NCDC) .

El Niño watch discontinued
Neutral El Niño conditions exist in the equatorial Pacific, where sea surface temperatures were 0.4°C above average as of November 12. NOAA's Climate Prediction Center (CPC) has cancelled their El Niño watch, and expects neutral El Niño conditions for the coming winter. Temperatures in the equatorial Eastern Pacific need to be 0.5°C above average or warmer to be considered an El Niño. El Niño conditions tend to bring cooler and wetter winter weather to the Southern U.S.


Figure 2. Arctic sea ice extent in October 2012 (thick black line) was the second lowest since satellite records began in 1979. Sea ice extent has sunk to the lowest values on record for this time of year during the first half of November. The previous record low occurred in 2007 (magenta line.) Image credit: National Snow and Ice Data Center (NSIDC) and meteomodel.pl.

Arctic sea ice falls to 2nd lowest October extent on record
Arctic sea ice extent during October reached its second lowest extent in the 35-year satellite record, behind 2007, according to the National Snow and Ice Data Center (NSIDC). Beginning in late October, Arctic sea ice extent began setting new daily record lows again, and it is very likely we will have a new monthly record low for the month of November. I have much more to say about this year's extraordinary loss of Arctic sea ice in my October 20, 2012 post, Earth's attic is on fire: Arctic sea ice bottoms out at a new record low.

Jeff Masters