April 2021 In Review

Temperatures finished near to slightly below normal on the whole across the area this April. The first 5 days featured record-territory warmth with highs in the 70s and 80s. In fact, Pierre and Mobridge set daily record highs on the 2^nd, 3^rd, and/or 4^th. However, much of the remainder of the month would feature near normal to below normal temperatures. Some of the coldest air was observed on the 19-25^th, when Pierre and Mobridge set at least one record low temperature each.

Brown/Spink Counties and areas to the east recorded above average amounts of precipitation (by as much as around three quarters of an inch at Aberdeen and Wheaton), while the rest of the area was below average (by as much as around an inch at Mobridge and Timber Lake). For those with a surplus, much of the rain fell over a 3-day period from April 6-8^th when a large, slow moving low pressure system tracked through. Daily records were set on the 7^th at Aberdeen, Watertown and Sisseton when over an inch fell. The bullseye of this system was across Day, Roberts, Big Stone, Clark, Codington and Grant Counties where there was a storm total of 3 to 4 plus inches of rain. This led to river rises to near action flood stage in a few cases. As far as snowfall goes, the whole area recorded below average amounts. There were just a few days where at least a trace of snow fell (a few of which led to icy roads), but the most notable in terms of accumulations took place on the 20^th from McPherson southeast to Deuel County during the afternoon and evening – up to 2 to 4” fell (fairly localized). Drought conditions worsened over the course of the month across north central SD, but improved or disappeared across portions of northeastern SD and west central MN.

Finally, below are the snowfall totals as of May 1^st for the 2020-2021 cold season vs normal (based on the 1981-2010 climate normals – an update to these normal will take place in a couple days on May 4^th).

Aberdeen: 31.7” vs 38.1” (-6.4”)

Watertown: 32.6” vs 35.9” (-3.3”)

Sisseton: 23.7” vs 44.5” (-20.8”)

Pierre: 24.2” vs 31.9” (-7.7”)

Mobridge: 17.2” vs 31.1” (-13.9”)

*April 2021*
Temperature Data	Aberdeen	Sisseton	Wheaton	Watertown
Warmest Temperature / Date	80 / 4^th	79 / 5^th	76 / 5^th	82 / 5^th
Coldest Temperature / Date	12 / 1^st	15 / 1^st	16 / 1^st	15 / 1^st
Average High / Departure from Normal	58.7 / +1.7	56.4 / +0.1	53.1 / -2.1	54.8 / -0.8
Average Low / Departure from Normal	30.6 / -1.2	33.0 / +0.4	32.7 / +0.7	31.2 / -0.9
Monthly Average / Departure from Normal	44.7 / +0.3	44.7 / +0.2	42.9 / -0.7	43.0 / -0.8
Precipitation Data
Monthly Precipitation / Departure from Normal	2.59 / +0.74	2.66 / +0.38	2.94 / +0.70	2.44 / +0.42
Most Precipitation in 24 hours / Date	1.41 / 7^th	1.56 / 7^th	1.24 / 7^th	1.01 / 7th
Monthly Snowfall / Departure from Normal	1.7 / -1.4	T / -3.8	T / -4.4	0.9 / -2.4
Most Snow in 24 hours / Date	1.6 / 20^th	T / 5 days	T / 4 days	0.6 / 20^th

Temperature Data	Pierre	Kennebec	Mobridge	Timber Lake
Warmest Temperature / Date	84 / 4^th	86 / 4^th	84 / 4^th	80 / 4^th, 5^th
Coldest Temperature / Date	18 / 20^th	14 / 20^th	17/20,21,24^th	16 / 21^st
Average High / Departure from Normal	59.2 / -0.5	61.9 / -0.3	60.0 / +2.0	58.8 / +0.0
Average Low / Departure from Normal	30.9 / -3.3	30.7 / -3.3	29.5 / -3.0	29.7 / -3.0
Monthly Average / Departure from Normal	45.1 / -1.9	46.5 / -1.6	44.7 / -0.6	44.5 / -1.3
Precipitation Data
Monthly Precipitation / Departure from Normal	1.28 / -0.53	1.90 / -0.26	0.50 / -1.07	0.74 / -0.96
Most Precipitation in 24 hours / Date	0.81 / 6^th	1.14 / 7^th	0.18 / 26^th	0.34 / 26^th
Monthly Snowfall / Departure from Normal	T / -4.1	T / -3.9	T / -3.2	T / -5.3
Most Snow in 24 hours / Date	T / 5 days	T / 20^th, 21^st	T / 5 days	T / 12,13,20^th

Average temperature departure from normal this April on the whole, courtesy of the Midwestern Regional Climate Center

Daily high temperatures (value) and departures from normal (box shading) at Aberdeen, Watertown and Pierre.

Total precipitation this April (left) and departures from normal (right), courtesy of the Midwestern Regional Climate Center

Total observed rainfall from April 6-8th.

Total snowfall this April (left) and departures from normal (right), courtesy of the Midwestern Regional Climate Center

US Drought Monitor comparison between the beginning (left) and end (right) of the month in South Dakota and Minnesota.

Total snowfall during the 2020-2021 cold season, as of May 1st, 2021, courtesy of the Midwestern Regional Climate Center