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weather mariposa december 7 2017

10th warmest autumn and low rainfall expanded drought across much of U.S. South

December 7, 2017 - Throughout many parts of the U.S., a warm, dry November made autumn seem more like an extension of late summer, allowing people to get out and enjoy the mild weather.

Here’s how last month, the fall and the year to date fared in terms of the climate record:  

Climate by the numbers

November 2017

The November average temperature for the contiguous U.S. was 45.1 degrees F, 3.4 degrees above average, making it the seventh warmest November on record, according to scientists from NOAA’s National Centers for Environmental Information. Record warmth spanned the Southwest with much-above-average temperatures stretching to the West Coast, Central Rockies and Southern Plains. The precipitation total for the month was 1.58 inches, 0.65 of an inch below average, making November the 19th driest on record.

Autumn 2017

The average autumn (September through November) U.S. temperature was 55.7 degrees F, 2.1 degrees above average, making it the 10th warmest autumn on record. Record warmth was observed in the Southwest and New England. Precipitation totaled 6.43 inches, 0.45 of an inch below average, putting this autumn among the driest third on record.  

The year to date (YTD)

The year to date (January through November) for the contiguous U.S. was the third warmest on record, with an average temperature of 56.4 degrees F, 2.6 degrees above average. All of the Lower 48 states and Alaska observed above-average temperatures during this 11-month period. YTD precipitation totaled 30.60 inches, 3.01 inches above normal, ranking it the ninth wettest such period on record.

See this map of notable climate events that occurred around the U.S during November and Fall 2017.
See this map of notable climate events that occurred around the U.S during November and Fall 2017. (NOAA NCEI)

More notable climate events include:

  • Record heat in the Southwest: Arizona, Colorado, New Mexico and Utah each had their warmest November on record. Arizona and New Mexico were also record-warm for autumn and the year to date.

  • Record-low rainfall in the South: November saw record low precipitation fall in parts of the Southwest and deep South. Mississippi ranked as third driest; Alabama and Arkansas tied for fourth, Oklahoma ranked fifth; and Louisiana ranked tenth. Arkansas saw its driest autumn on record; the state received 36.1 percent of its average rainfall this fall.

  • A warm, dry fall expanded drought in South: On November 28, 21.1 percent of the contiguous U.S. was in drought, up nearly 9.2 percent compared with the end of October. Drought developed, expanded and intensified in the Southwest, Southern Plains, Lower Mississippi Valley and Southeast.

  • A wet year for parts of West and the Great Lakes: Many locations across the West and Great Lakes had much-above-average precipitation totals for the year to date. Michigan had its wettest January-November on record with 37.31 inches of precipitation, 8.19 inches above average.

More: Find NOAA’s report and download related maps and images by visiting the NCEI website.
Source: NOAA