Weather on May 21
Sioux Falls, SD
55 Years of Data
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 56 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.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 69° | 45° | 57° | — | — |
| 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° | — | — |
Sioux Falls, SD Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Sioux Falls, SD Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Sioux Falls, SD Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Sioux Falls, SD
Sioux Falls, SD has no months that meet our "pleasant" threshold — every season has tradeoffs.