Weather on September 20 at Great Sand Dunes
Great Sand Dunes National Park and Preserve
Based on 55 years of data from Alamosa, CO
Elevation Note: Great Sand Dunes sits at 8,200 ft. Expect temperatures 29°F cooler than the data shown below, which comes from Alamosa, CO at a lower elevation.
Planning Your Visit
September 20th in Great Sand Dunes National Park (via Alamosa, CO) typically brings pleasant fall weather, with average highs around 72°F and lows near 35°F — a 37°F daily swing. Over 55 years of records, the warmest September 20th was in 2010 (64°F average), while the coldest was 1971 (42°F) — a 22°F range across recorded history. Rain or other precipitation has occurred on about 22% of September 20th dates historically, with the wettest September 20th recording 1.93" of rain. The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.
Planning for September 20th in Great Sand Dunes? Great weather for outdoor activities.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 77°F | 34°F | 0" | 0" |
| 2024 | 76°F | 33°F | 0" | 0" |
| 2023 | 67°F | 31°F | 0" | 0" |
| 2022 | 80°F | 38°F | 0" | 0" |
| 2021 | 77°F | 40°F | 0" | 0" |
| 2020 | 77°F | 42°F | 0" | 0" |
| 2019 | 76°F | 38°F | 0" | 0" |
| 2018 | 81°F | 46°F | 1.07" | 0" |
| 2017 | 71°F | 41°F | 0" | 0" |
| 2016 | 82°F | 39°F | 0" | 0" |
| 2015 | 78°F | 36°F | 0" | 0" |
| 2014 | 83°F | 42°F | 0" | 0" |
| 2013 | 72°F | 39°F | 0.08" | 0" |
| 2012 | 77°F | 30°F | 0" | 0" |
| 2011 | 73°F | 33°F | 0" | -- |
| 2010 | 84°F | 45°F | 0" | 0" |
| 2009 | 79°F | 30°F | 0" | 0" |
| 2008 | 73°F | 31°F | 0" | 0" |
| 2007 | 74°F | 33°F | 0" | 0" |
| 2006 | 71°F | 28°F | 0.38" | 0" |
| 2005 | 78°F | 28°F | -- | 0" |
| 2004 | 69°F | 43°F | 0" | 0" |
| 2003 | 73°F | 29°F | 0" | 0" |
| 2002 | 68°F | 31°F | 0" | 0" |
| 2001 | 77°F | 32°F | 0" | 0" |
| 2000 | 74°F | 40°F | 0" | 0" |
| 1999 | 68°F | 33°F | 0.15" | 0" |
| 1998 | 77°F | 33°F | 0" | 0" |
| 1997 | 61°F | 46°F | 1.93" | 0" |
| 1996 | 64°F | 28°F | 0" | 0" |
| 1995 | 73°F | 35°F | 0" | 0" |
| 1994 | 68°F | 37°F | 0.03" | 0" |
| 1993 | 74°F | 28°F | 0" | 0" |
| 1992 | 65°F | 34°F | 0.03" | 0" |
| 1991 | 72°F | 31°F | 0" | 0" |
| 1990 | 65°F | 37°F | 0.33" | 0" |
| 1989 | 70°F | 42°F | 0.08" | 0" |
| 1988 | 74°F | 26°F | 0" | 0" |
| 1987 | 74°F | 28°F | 0" | 0" |
| 1986 | 75°F | 38°F | 0" | 0" |
| 1985 | 53°F | 40°F | 1.09" | 0" |
| 1984 | 76°F | 37°F | 0" | 0" |
| 1983 | 66°F | 34°F | 0" | 0" |
| 1982 | 62°F | 45°F | 1.35" | 0" |
| 1981 | 77°F | 32°F | 0" | 0" |
| 1980 | 76°F | 40°F | 0" | 0" |
| 1979 | 72°F | 38°F | 0.05" | 0" |
| 1978 | 63°F | 29°F | 0" | 0" |
| 1977 | 74°F | 41°F | 0" | 0" |
| 1976 | 71°F | 35°F | 0" | 0" |
| 1975 | 67°F | 28°F | 0" | 0" |
| 1974 | 72°F | 34°F | 0" | 0" |
| 1973 | 79°F | 32°F | 0" | 0" |
| 1972 | 66°F | 36°F | 0" | 0" |
| 1971 | 64°F | 20°F | 0" | 0" |