Weather on September 20
Sioux Falls, SD
55 Years of Data
Avg High
72°F
Avg Low
48°F
Warmest
2019
79°F avg
Coldest
1983
40°F avg
About This Date
September 20th in Sioux Falls, SD typically brings pleasant fall weather, with average highs around 72°F and lows near 48°F. Over 55 years of records, the warmest September 20th was in 2019 (79°F average), while the coldest was 1983 (40°F) — a 39°F range across recorded history. Rain or other precipitation has occurred on about 25% of September 20th dates historically, with the wettest September 20th recording 7.8" of rain. The last decade has been 10.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 10.5°F warmer on this date compared to 20-30 years ago.
Planning for September 20th in Sioux Falls, SD? Great weather for outdoor activities.
Warming Trend
2.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 73° | 53° | 63° | — | — |
| 2024 | 87° | 52° | 69° | — | — |
| 2023 | 88° | 56° | 72° | — | — |
| 2022 | 95° | 60° | 78° | — | — |
| 2021 | 77° | 50° | 64° | 2.97" | — |
| 2020 | 80° | 58° | 69° | — | — |
| 2019warmest | 87° | 72° | 79° | — | — |
| 2018 | 69° | 55° | 62° | 7.8" | — |
| 2017 | 74° | 50° | 62° | — | — |
| 2016 | 86° | 54° | 70° | — | — |
| 2015 | 78° | 54° | 66° | — | — |
| 2014 | 84° | 56° | 70° | 0.03" | — |
| 2013 | 64° | 40° | 52° | — | — |
| 2012 | 68° | 45° | 56° | — | — |
| 2011 | 68° | 53° | 61° | 0.08" | — |
| 2010 | 87° | 53° | 70° | 0.03" | — |
| 2009 | 79° | 52° | 65° | — | — |
| 2008 | 84° | 58° | 71° | — | — |
| 2007 | 90° | 56° | 73° | — | — |
| 2006 | 63° | 30° | 46° | — | — |
| 2005 | 87° | 57° | 72° | — | — |
| 2004 | 75° | 63° | 69° | 1.65" | — |
| 2003 | 74° | 49° | 61° | — | — |
| 2002 | 78° | 51° | 65° | — | — |
| 2001 | 74° | 51° | 62° | 0.48" | — |
| 2000 | 59° | 36° | 47° | — | — |
| 1999 | 58° | 34° | 46° | — | — |
| 1998 | 73° | 45° | 59° | — | — |
| 1997 | 60° | 37° | 49° | — | — |
| 1996 | 56° | 50° | 53° | 0.1" | — |
| 1995 | 50° | 41° | 46° | — | — |
| 1994 | 83° | 60° | 71° | — | — |
| 1993 | 57° | 53° | 55° | — | — |
| 1992 | 78° | 52° | 65° | — | — |
| 1991 | 72° | 38° | 55° | — | — |
| 1990 | 76° | 56° | 66° | 0.03" | — |
| 1989 | 81° | 63° | 72° | 0.43" | — |
| 1988 | 66° | 45° | 55° | — | — |
| 1987 | 66° | 44° | 55° | — | — |
| 1986 | 73° | 47° | 60° | 0.64" | — |
| 1985 | 57° | 42° | 50° | — | — |
| 1984 | 77° | 49° | 63° | — | — |
| 1983coldest | 50° | 30° | 40° | 0.13" | — |
| 1982 | 58° | 39° | 48° | — | — |
| 1981 | 86° | 46° | 66° | — | — |
| 1980 | 67° | 47° | 57° | 0.58" | — |
| 1979 | 67° | 45° | 56° | — | — |
| 1978 | 59° | 43° | 51° | — | — |
| 1977 | 73° | 42° | 58° | — | — |
| 1976 | 71° | 38° | 54° | — | — |
| 1975 | 51° | 44° | 48° | — | — |
| 1974 | 68° | 43° | 55° | — | — |
| 1973 | 63° | 45° | 54° | — | — |
| 1972 | 80° | 43° | 61° | 0.66" | — |
| 1971 | 76° | 40° | 58° | — | — |
55 years of data from SIOUX FALLS