Climate bulletin - August 2014
Summary of the world's climate in August 2014.
The global average temperature for August 2014 as estimated from the HadCRUT4 data set was 0.67 ± 0.22 °C above the 1961-1990 average. Although the central estimate of 0.67 °C for August 2014 suggests that it was the warmest August on record, the difficulties of measuring global average temperature are such that it is not possible to provide a definitive ranking. Other very warm Augusts were comparable within the estimated margin of error. Other global temperature data sets maintained by NASA GISS and NOAA NCDC also show that August was a very warm month globally. Sea-surface temperatures in the tropical Pacific were close to or above average in August, but did not exceed El Niño thresholds. They were particularly high (relative to average) in the western Pacific.
During August, the global average air temperature over land was warmer than the long term average (0.81 ± 0.28°C). There were some areas where temperatures were cooler than average, but the most notable cold temperatures were reported in China and northern Australia where temperatures were below the 2nd percentile of occurrence. Unusual warmth was more widespread, with central America, southern South America, parts of Alaska, north east Canada, north east Russia, south west Australia and an area extending from North Africa through the middle east into Eastern Europe and western Russia all exceeding the 10th percentile of occurrence.
Sea-surface temperatures were generally warmer than average in August. The global mean sea-surface temperature was 0.65 ± 0.08 °C above the long term average. The northern hemisphere was particularly warm, with the northern hemisphere average being 0.93 ± 0.07 °C above the 1961-1990 average. This was warmer than any previous August in the record for that region. Unusually high sea-surface temperatures were widespread in August 2014 with large areas of the North Pacific, North Atlantic and Tropical Indian Ocean exceeding the 10th percentile of occurrence. Unusually high temperatures also extended into the Labrador Sea and parts of the Arctic Ocean. Below average sea-surface temperatures were measured in the South Atlantic, south east Pacific and areas of the Southern Ocean (although there are few measurements from the Southern Oceans available during the winter months).
In the southern hemisphere, the sea ice surrounding Antarctica reached a record extent for August. In the Arctic, August sea ice extent was the seventh lowest on record. In each case, the record is the passive microwave satellite record that begins in 1979.