Weather on May 21
Sioux Falls, SD
55 Years of Data
Avg High
72°F
Avg Low
49°F
Warmest
1973
75°F avg
Coldest
2022
45°F avg
About This Date
May 21st in Sioux Falls, SD typically brings pleasant spring weather, with average highs around 72°F and lows near 49°F. Over 55 years of records, the warmest May 21st was in 1973 (75°F average), while the coldest was 2022 (45°F) — a 30°F range across recorded history. Rain or other precipitation has occurred on about 36% of May 21st dates historically, with the wettest May 21st recording 2.95" of rain. The last decade has been 3.5°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.5°F cooler on this date compared to 20-30 years ago.
Planning for May 21st in Sioux Falls, SD? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Cooling Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 52° | 38° | 45° | — | — |
| 2024 | 63° | 50° | 56° | 2.95" | — |
| 2023 | 84° | 46° | 65° | — | — |
| 2022coldest | 53° | 37° | 45° | — | — |
| 2021 | 84° | 63° | 73° | — | — |
| 2020 | 70° | 58° | 64° | — | — |
| 2019 | 52° | 46° | 49° | 2.44" | — |
| 2018 | 68° | 53° | 61° | 0.33" | — |
| 2017 | 60° | 36° | 48° | 0.03" | — |
| 2016 | 73° | 44° | 59° | — | — |
| 2015 | 75° | 42° | 59° | — | — |
| 2014 | 72° | 46° | 59° | — | — |
| 2013 | 61° | 51° | 56° | 0.08" | — |
| 2012 | 74° | 45° | 59° | — | — |
| 2011 | 74° | 54° | 64° | 1.57" | — |
| 2010 | 74° | 55° | 64° | — | — |
| 2009 | 62° | 52° | 57° | 0.18" | — |
| 2008 | 73° | 35° | 54° | — | — |
| 2007 | 83° | 65° | 74° | — | — |
| 2006 | 64° | 48° | 56° | 0.08" | — |
| 2005 | 81° | 55° | 68° | 0.53" | — |
| 2004 | 78° | 57° | 68° | 1.3" | — |
| 2003 | 67° | 35° | 51° | — | — |
| 2002 | 71° | 42° | 57° | — | — |
| 2001 | 55° | 43° | 49° | 0.03" | — |
| 2000 | 78° | 47° | 62° | — | — |
| 1999 | 73° | 48° | 61° | — | — |
| 1998 | 74° | 56° | 65° | — | — |
| 1997 | 73° | 41° | 57° | — | — |
| 1996 | 75° | 48° | 62° | — | — |
| 1995 | 75° | 44° | 60° | — | — |
| 1994 | 83° | 61° | 72° | — | — |
| 1993 | 72° | 37° | 54° | — | — |
| 1992 | 79° | 65° | 72° | — | — |
| 1991 | 83° | 63° | 73° | — | — |
| 1990 | 62° | 49° | 55° | — | — |
| 1989 | 78° | 48° | 63° | 0.2" | — |
| 1988 | 69° | 57° | 63° | 0.69" | — |
| 1987 | 65° | 41° | 53° | 0.05" | — |
| 1986 | 72° | 42° | 57° | — | — |
| 1985 | 74° | 40° | 57° | — | — |
| 1984 | 78° | 55° | 67° | 0.41" | — |
| 1983 | 74° | 48° | 61° | — | — |
| 1982 | 56° | 49° | 52° | 0.05" | — |
| 1981 | 79° | 56° | 67° | 0.1" | — |
| 1980 | 80° | 43° | 61° | — | — |
| 1979 | 65° | 36° | 50° | — | — |
| 1978 | 74° | 39° | 56° | — | — |
| 1977 | 73° | 58° | 65° | 2.11" | — |
| 1976 | 86° | 60° | 73° | 0.33" | — |
| 1975 | 78° | 54° | 66° | — | — |
| 1974 | 72° | 52° | 62° | 1.52" | — |
| 1973warmest | 89° | 60° | 75° | — | — |
| 1972 | 86° | 59° | 73° | — | — |
| 1971 | 75° | 50° | 63° | — | — |
55 years of data from SIOUX FALLS