The National Climatic Data Center preliminary analysis for October was posted late Friday. Unlike the cold average for the U.S., the average global temperature for land and ocean combined was 0.57°C (1.03°F) above the 20th century average of 14.0°C (57.1°F). This makes it the sixth warmest in history. The average land temperature alone was also the sixth warmest, while the average ocean temperature was the fifth warmest. For the year to date, the January through October average is tied with 2007 as the fifth warmest. (Note: The preliminary analysis was made before data from Canada were available, so global averages may change slightly.)
Other than the U.S. and northern Europe, nearly all land areas were warmer than average. The warmest regions relative to normal were in the high latitudes of the Northern Hemisphere, particularly Alaska and northern and eastern Russia. In the Southern Hemisphere, New Zealand reported the coldest October in 64 years, with some all-time record low October temperatures. On the other hand, Darwin, Australia had its warmest month since records began in 1941:
The previous record for the month of October and for any month of the year was 34.4°C, most recently in October 2008. This October, the daily maximum temperature during the month reached 35.0°C on 13 days, the highest on record for any month, and there were another 4 days with 34.9°C.Record warm temperatures have continued into November in Australia, where Adelaide in South Australia has recorded its first ever spring heatwave of 8 consecutive days above 35°C; 5 consecutive days are required for a heatwave, and the previous record was 4 in 1894.
Images (click to enlarge): October 2009 global temperature departures from average, historical departures since 1880; from National Climatic Data Center