Weather on December 21 at Gateway Arch
Gateway Arch National Park
Based on 54 years of data from St. Louis, MO
Planning Your Visit
December 21st in Gateway Arch National Park (via St. Louis, MO) typically brings chilly winter weather, with average highs around 43°F and lows near 25°F. Over 54 years of records, the warmest December 21st was in 2015 (52°F average), while the coldest was 1989 (-4°F) — a 56°F range across recorded history. Precipitation has occurred on 30% of recorded December 21st dates, with snow falling 2% of the time. The last decade has been 8.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 8.0°F warmer on this date compared to 20-30 years ago.
Planning for December 21st in Gateway Arch? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 47°F | 21°F | 0" | 0" |
| 2024 | 39°F | 24°F | 0" | 0" |
| 2023 | 59°F | 36°F | 0.03" | -- |
| 2022 | 39°F | 24°F | 0" | 0" |
| 2021 | 51°F | 24°F | 0" | 0" |
| 2020 | 59°F | 37°F | 0" | 0" |
| 2019 | 49°F | 20°F | 0" | 0" |
| 2018 | 38°F | 27°F | 0" | 0" |
| 2017 | 56°F | 39°F | 0" | 0" |
| 2016 | 52°F | 20°F | 0" | 0" |
| 2015 | 56°F | 48°F | 0.46" | 0" |
| 2014 | 41°F | 37°F | 0" | 0" |
| 2013 | 69°F | 33°F | 1.52" | 0" |
| 2012 | 38°F | 25°F | 0.08" | 0" |
| 2011 | 49°F | 43°F | 0.3" | -- |
| 2010 | 44°F | 32°F | 0" | 0" |
| 2009 | 34°F | 26°F | 0" | 0" |
| 2008 | 38°F | 6°F | 0" | 0" |
| 2007 | 45°F | 38°F | 0.89" | 0" |
| 2006 | 54°F | 30°F | 2.13" | 0" |
| 2005 | 35°F | 16°F | 0" | 0" |
| 2004 | 37°F | 14°F | 0" | 0" |
| 2003 | 53°F | 27°F | 0" | 0" |
| 2002 | 50°F | 34°F | 0" | 0" |
| 2001 | 53°F | 25°F | 0" | 0" |
| 2000 | 26°F | 9°F | 0" | 0" |
| 1999 | 35°F | 14°F | 0" | 0" |
| 1998 | 40°F | 32°F | 0.46" | 0" |
| 1997 | 36°F | 32°F | 0" | 0" |
| 1996 | 27°F | 10°F | 0" | 0" |
| 1995 | 27°F | 23°F | 0" | 0" |
| 1994 | 46°F | 40°F | 0.51" | 0" |
| 1993 | 43°F | 26°F | 0" | 0" |
| 1992 | 48°F | 23°F | 0" | 0" |
| 1991 | 37°F | 35°F | 0.53" | 0" |
| 1990 | 51°F | 7°F | 3.68" | 0" |
| 1989 | 10°F | -18°F | 0.1" | 0.5" |
| 1988 | 67°F | 29°F | 0" | 0" |
| 1987 | 49°F | 30°F | 0" | 0" |
| 1986 | 44°F | 22°F | 0" | 0" |
| 1985 | 24°F | 10°F | 0" | 0" |
| 1984 | 63°F | 30°F | 0" | 0" |
| 1982 | 48°F | 25°F | 0" | 0" |
| 1981 | 33°F | 1°F | 0.13" | -- |
| 1980 | 24°F | 10°F | 0" | 0" |
| 1979 | 58°F | 34°F | 0" | 0" |
| 1978 | 65°F | 24°F | 0.08" | 0" |
| 1977 | 32°F | 18°F | 0" | 0" |
| 1976 | 37°F | 9°F | 0" | 0" |
| 1975 | 38°F | 24°F | 0" | 0" |
| 1974 | 51°F | 33°F | 0" | 0" |
| 1973 | 16°F | -- | 0" | 0" |
| 1972 | 36°F | 32°F | 0.03" | 0" |
| 1971 | 48°F | 37°F | 0.05" | 0" |