January 2021 In Review: Very Mild

January 2021 finished well above normal temperature-wise as a whole, between 8 and 13 degrees for most. In fact, Kennebec recorded their 10^th warmest January on record; Watertown 7^th, Timber Lake 5^th, Aberdeen, Pierre and Sisseton 4^th, and Mobridge 2^nd (the top two warmest Januaries at most locations were 2006 and 1990). Looking at the warmth another way, a number of locations failed to drop below zero degrees all month long. This includes Pierre (has happened only 5 other years on record, and the average is 9 sub-zero days per January), Timber Lake (3 other years, averages 12 sub-zero days), Aberdeen (two other years – 2006 and 1990, average is 14 sub-zero days), Sisseton (one other year – 2006, averages 13 days), Mobridge (one other year – 2006, averages 13 days) and Watertown (one other year – 2006, averages 14 days). A number of daily warm low temperature records were set at several locations, particularly on the 13^th and 14^th.

Looking at the winter more broadly, this mild January picked up where the mild December left off. With two-thirds of meteorological winter (Dec, Jan and Feb) now finished, Watertown has recorded their 5^th warmest winter to date on record, 3^rd at Pierre and Sisseton, 2^nd at Kennebec and Aberdeen, and 1^st at Timber Lake and Mobridge. Unfortunately, one of the side-effects of such a mild winter is thin ice on area lakes – there were several incidences of people falling through.

In terms of precipitation, January 2021 finished below average both in terms of snowfall and liquid equivalent for the vast majority of the area. While a couple daily snowfall records were set on the 23^rd at Watertown and Pierre, amounts were under 2” in both cases. The main storm system this January manifested in the form of high winds across the entire forecast area, as well as blizzard conditions across portions of eastern South Dakota on the 14^th and 15^th. Much more information on this event can be found here: https://www.weather.gov/abr/2021_January_14-15_BlizzardHighWind  

*Wheaton: temperature data for the second half of the month is missing due to data quality issues. 

January 2021 temperature departures from normal, courtesy of the Midwestern Regional Climate Center

January 2021 temperature departures from normal on a regional scale, courtesy of the High Plains Regional Climate Center

January 2021 total precipitation (left) and departure from normal (right), courtesy of the Midwestern Regional Climate Center

January 2021 total snowfall (left) and departure from normal (right), courtesy of the Midwestern Regional Climate Center

The Accumulated Winter Season Severity Index through early February, from the Midwestern Regional Climate Center. This index shows how severe the winter has been thus far. Most of our area is in the "Mild" category, with some in the "Moderate" category. 

Specific plots of the Accumulated Winter Season Severity Index at Aberdeen, Pierre and Watertown (from top to bottom, respectively)