It’s a frequent refrain that comes with the beginning of fall. Some grumble as they pull jackets out of closets, or experience that first biting jet of cold wind, easily forgetting the summer high temperatures. Others use the colder weather as a way to publicly doubt the basic science of the greenhouse effect. Even if your state’s now hit “jacket weather,” a new report shows how this year, and last month, were much warmer than average.
This September was the the fourth-warmest on record across the globe, and the sixth-warmest in the United States, according to the State of the Climate report for that month. The report is issued by the National Climatic Data Center (NCDC), which is the part of the National Oceanic and Atmospheric Administration (NOAA). It’s the place to go for historic climate and weather data.
This means September was 1.15°F warmer than the 20th century global average across land and ocean. The same was true for the year so far — January-September was 1.08°F above the same average. The temperature over the contiguous U.S. was 2.5°F warmer than the 20th century average. The West, Great Plains, and much of the Gulf Coast were warmer than average. Idaho, Montana, Wyoming, Colorado, North Dakota, South Dakota, and Nebraska had top ten warmest Septembers.
The world’s six hottest Septembers have all occurred since 2003. This map shows the areas that experienced record warm or cold temperatures, and warmer-than-average or colder-than-average temperatures.
For people who live in the eastern part of the U.S., September was not much hotter than average. But it’s easy to see that there are far more areas across the globe that are warmer than average than colder, and many places had record highs. South America and eastern South Africa may have felt cooler than normal in September, but the Southern Hemisphere as a whole experienced a record warm.
This is largely because Australia had its hottest September since records began — 4.95°F above the 1961-1990 average. The three souther Australian states had record average, maximum, and minimum September temperatures. Way up in the north, Norway had a very warm month, with the far northeastern town of Vardo marking down an average September temperature above 50°F for the first time.
The eastern and central Pacific Ocean continued to experience neutral temperatures, the rest of the ocean — particularly the South Pacific and South Indian oceans as well as the Barents Sea in the far north — had pockets of record warmth.
Above-average precipitation also occurred in places across the globe, with part of the central U.S., some of western Russia, and southwestern Australia had record rainfall. The national average precipitation in the U.S. was 0.51 inches above normal, which is the 12th wettest on record. Record dryness, however, was widespread in northern Europe, some of southwestern Asia and northern and far southern Africa, parts of northern Australia, and north central Chile.
This interactive map from the Weather Channel shows how each state stacks up in terms of rainfall and dryness.
2013 won’t be the warmest year on record, but the overall trend shows that the world is warming: the nine hottest years on record were all since 1998. And the NCDC report makes clear that even if you had to grab for a jacket earlier than you wanted to, the world as a whole was a lot hotter than normal.