Weather on September 18
Sioux Falls, SD
55 Years of Data
Avg High
74°F
Avg Low
51°F
Warmest
2013
77°F avg
Coldest
1991
37°F avg
About This Date
September 18th in Sioux Falls, SD typically brings pleasant fall weather, with average highs around 74°F and lows near 51°F. Over 55 years of records, the warmest September 18th was in 2013 (77°F average), while the coldest was 1991 (37°F) — a 40°F range across recorded history. Rain or other precipitation has occurred on about 27% of September 18th dates historically, with the wettest September 18th recording 5.26" of rain. The last decade has been 2.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.4°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Sioux Falls, SD? Great weather for outdoor activities.
Warming Trend
1.2°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 60° | 69° | — | — |
| 2024 | 85° | 69° | 77° | — | — |
| 2023 | 87° | 59° | 73° | — | — |
| 2022 | 77° | 53° | 65° | — | — |
| 2021 | 85° | 49° | 67° | — | — |
| 2020 | 71° | 44° | 58° | — | — |
| 2019 | 79° | 61° | 70° | — | — |
| 2018 | 70° | 61° | 65° | 1.8" | — |
| 2017 | 75° | 58° | 66° | 0.05" | — |
| 2016 | 83° | 58° | 70° | — | — |
| 2015 | 59° | 47° | 53° | 0.15" | — |
| 2014 | 77° | 52° | 64° | — | — |
| 2013warmest | 88° | 66° | 77° | — | — |
| 2012 | 68° | 34° | 51° | — | — |
| 2011 | 74° | 49° | 61° | — | — |
| 2010 | 50° | 40° | 45° | 0.13" | — |
| 2009 | 84° | 53° | 69° | — | — |
| 2008 | 82° | 51° | 67° | — | — |
| 2007 | 77° | 52° | 64° | 0.51" | — |
| 2006 | 51° | 43° | 47° | 0.08" | — |
| 2005 | 82° | 52° | 67° | 0.05" | — |
| 2004 | 84° | 54° | 69° | — | — |
| 2003 | 57° | 38° | 47° | 1.73" | — |
| 2002 | 79° | 57° | 68° | 1.17" | — |
| 2001 | 64° | 54° | 59° | — | — |
| 2000 | 83° | 67° | 75° | — | — |
| 1999 | 82° | 52° | 67° | — | — |
| 1998 | 90° | 63° | 76° | — | — |
| 1997 | 85° | 60° | 72° | — | — |
| 1996 | 62° | 50° | 56° | — | — |
| 1995 | 62° | 55° | 59° | 1.52" | — |
| 1994 | 82° | 46° | 64° | — | — |
| 1993 | 61° | 49° | 55° | — | — |
| 1992 | 60° | 42° | 51° | — | — |
| 1991coldest | 45° | 30° | 37° | — | — |
| 1990 | 65° | 55° | 60° | 0.58" | — |
| 1989 | 84° | 63° | 73° | — | — |
| 1988 | 83° | 63° | 73° | 0.76" | — |
| 1987 | 65° | 45° | 55° | — | — |
| 1986 | 60° | 51° | 56° | 5.26" | — |
| 1985 | 83° | 65° | 74° | — | — |
| 1984 | 91° | 57° | 74° | — | — |
| 1983 | 69° | 45° | 57° | — | — |
| 1982 | 71° | 39° | 55° | — | — |
| 1981 | 79° | 38° | 58° | — | — |
| 1980 | 64° | 51° | 58° | — | — |
| 1979 | 70° | 48° | 59° | — | — |
| 1978 | 80° | 55° | 68° | 0.28" | — |
| 1977 | 68° | 53° | 61° | 0.08" | — |
| 1976 | 87° | 58° | 72° | — | — |
| 1975 | 64° | 48° | 56° | — | — |
| 1974 | 91° | 45° | 68° | — | — |
| 1973 | 69° | 36° | 52° | — | — |
| 1972 | 87° | 47° | 67° | — | — |
| 1971 | 62° | 34° | 48° | — | — |
55 years of data from SIOUX FALLS