The unprecedented heat helped strengthen wildfires and deepen ingrained drought.
The average temperature for September through November was 57.6 degrees Fahrenheit in the contiguous U.S., not too torrid-sounding until you consider the historical average is 53.5 degrees. November in particular was balmy, ranking second place in heat for the month in 122 years of records. The three months combined represent the hottest-known fall in U.S. history, nudging out last autumn’s (until now) unprecedented temperature of 56.8 degrees.
The late-year warmth allowed people in normally frigid regions like Alaska—which is firmly on track to log its hottest-known year—to rock breezy wardrobes more suitable for spring. On the less-positive side, it also contributed to devastating wildfires and drought. Here’s more from NOAA’s latest climate analysis:
The contiguous U.S. drought footprint expanded from 19.5 percent on August 30 to 31.5 percent on November 29. Drought intensified and expanded dramatically in the Southeast during autumn. By season's end, Exceptional Drought ("D4", the most severe category) had established across northern Georgia, northern Alabama, and the Appalachian portions of the Carolinas and Tennessee. Drought also worsened in the ArkLaTex, Southern Plains and Northeast….
Wildfire activity was higher than normal during November. Many of the fires were concentrated in the drought-stricken areas of the Southeast. Nationally, the number of fires for the month was the second highest since records began in 2000. The 8,560 fires were only behind the 10,223 fires in 2001. There were a total of 275,616 acres burned, the fourth most on record.
In terms of all of 2016, 47 of the Lower 48 states have seen temperatures ranking among their top-five hottest such periods on record. Only Louisiana stands outside this sweaty group, with a year-to-date temperature measuring as sixth warmest.