December 2021

December 2021 finished near to above average by about 1 to 3 degrees. That said, there was a clear difference between the beginning and end, from record-breaking warmth to bitter cold. Daily record highs were set or tied on the 23^rd at Sisseton, 24^th at Sisseton and Pierre, and on the 1^st at Aberdeen, Sisseton and Mobridge. Mobridge also set a monthly record high on the 1^st – Mobridge had never reached 71 F in December before this year in recorded history (70 on Dec 6^th in 1939). This was only the 2^nd time Mobridge had reached 70 F in December. Similarly, Pierre reached 71 F on the 1^st, which was only the 7^th time a 70 F temp had been recorded in December; Sisseton 62 F on the 1^st, only the 10^th time a 60 F temp had been recorded; Aberdeen 65 F on the 1^st, only the 2^nd time a 65 F temp had been recorded.

While central South Dakota finished below average in terms of precipitation and snowfall for the most part this December, there were several bouts of snow across northeastern SD and west central MN. This included events on the 4^th, 7^th, a heavy banded snow event on the 17^th (totals of over a foot in Marshall County), and on the 25^th and 26^th. In fact, this was the 4^th wettest December on record at Sisseton and the 2^nd snowiest, and it was the 2^nd wettest at Wheaton and 5^th snowiest. Both Aberdeen and Sisseton set daily snowfall records on the 17^th.  

December 2021 temperature departure from normal, from the Midwestern Regional Climate Center

Daily high temperatures (numbers) and departures from normal (shading) through December 2021 for 5 different sites.

December 2021 precipitation totals (left) and departures from normal (right), from the Midwestern Regional Climate Center

December 2021 snowfall totals (left) and departures from normal (right), from the Midwestern Regional Climate Center

The Accumulated Winter Season Severity Index from the Midwestern Regional Climate Center depicts a top of the scale "Mild" start to the cold season (red dots), as of January 1st, 2022, across not only South Dakota, but much of the United States. 

Below are specific AWSSI graphs for Aberdeen, Pierre and Watertown (in that order), showing the category for each location through time (solid line) compared to the range of what has been observed historically (background shading). 

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2021 on the Whole

2021 finished well above average temperature-wise across the board, by 1 to 4 degrees. In fact (after excluding years with excessive missing data), Watertown and Wheaton recorded their tied 9^th warmest year on record, Aberdeen and Mobridge their 4^th warmest year on record, Sisseton 2^nd, and Timber Lake 1^st. There were still periods of extreme cold however, particularly in February. The difference between the highest and lowest observed temperature was 120 F at Sisseton, 124 F at Wheaton, 126 F at Watertown, 129 F at Aberdeen, 132 F at Pierre, 133 F at Kennebec, and 134 F at Mobridge, and Timber Lake.

Yearly precipitation ranged quite a bit across the forecast area, from locally 6+ inches above normal in a pocket across far northeastern SD and west central MN (Sisseton recorded their 8^th wettest year on record) to between 2 and 6+ inches below normal across much of the area along and west of the James River Valley. Severe to Extreme Drought peaked during the summer months for many across this area. Snowfall, however, was unanimously below normal this year (January 1^st through December 31^st, not seasonally from one year into another) from near normal to 30 inches or more. In fact (after excluding years with excessive missing data), Mobridge recorded their 5^th least snowy year on record, and Timber Lake their least snowy year on record. For additional, more detailed information about 2021’s weather, see the bottom of the page.

2021 temperature departure from normal, from the Midwestern Regional Climate Center

2021 precipitation totals (left) and departures from normal (right), from the Midwestern Regional Climate Center

2021 snowfall totals (left) and departures from normal (right), from the Midwestern Regional Climate Center

2021 temperature, precipitation and snow observations at Aberdeen, Pierre and Watertown:

For write-ups on some of the more notable events from 2021 (and before), visit

https://www.weather.gov/abr/events 

Links to all the 2021 monthly summaries: 

Jan: https://www.weather.gov/abr/January2021InReviewVeryMild

Feb: https://www.weather.gov/abr/February2021InReview

Mar: https://www.weather.gov/abr/March2021InReview

Apr: https://www.weather.gov/abr/April2021InReview

May: https://www.weather.gov/abr/May2021InReview

June: https://www.weather.gov/abr/June2021InReview

July: https://www.weather.gov/abr/July2021InReview

Aug: https://www.weather.gov/abr/August2021InReview

Sept: https://www.weather.gov/abr/September2021InReview

Oct: https://www.weather.gov/abr/October2021InReview

Nov: https://www.weather.gov/abr/November2021InReview

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