Weather on September 18 at Gateway Arch
Gateway Arch National Park
Based on 53 years of data from St. Louis, MO
Planning Your Visit
September 18th in Gateway Arch National Park (via St. Louis, MO) typically brings warm fall weather, with average highs around 80°F and lows near 57°F. Over 53 years of records, the warmest September 18th was in 1972 (85°F average), while the coldest was 1991 (50°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 26% of September 18th dates historically, with the wettest September 18th recording 4.29" of rain. The last decade has been 6.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.6°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Gateway Arch? Stay hydrated and seek shade during peak afternoon hours.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 95°F | 57°F | 0" | 0" |
| 2024 | 89°F | 56°F | 0" | 0" |
| 2023 | 80°F | 48°F | 0" | 0" |
| 2022 | 88°F | 62°F | 0" | 0" |
| 2021 | 90°F | 65°F | 0" | 0" |
| 2020 | 74°F | 53°F | 0" | 0" |
| 2019 | 91°F | 65°F | 0" | 0" |
| 2018 | 94°F | 68°F | 0" | 0" |
| 2017 | 84°F | 66°F | 0" | 0" |
| 2016 | 83°F | 64°F | 0" | 0" |
| 2015 | 90°F | 74°F | 0" | 0" |
| 2014 | 68°F | 58°F | 0" | 0" |
| 2013 | 78°F | 64°F | 0.58" | 0" |
| 2012 | 74°F | 51°F | 2.21" | 0" |
| 2011 | 69°F | 56°F | 0.03" | -- |
| 2010 | 81°F | 57°F | 0" | 0" |
| 2009 | 78°F | 56°F | 0" | 0" |
| 2008 | 78°F | 53°F | 0" | 0" |
| 2007 | 88°F | 61°F | 0" | 0" |
| 2006 | 85°F | 59°F | 3.15" | 0" |
| 2005 | 76°F | 55°F | 0" | 0" |
| 2004 | 81°F | 53°F | 0" | 0" |
| 2003 | 82°F | 62°F | 0" | 0" |
| 2002 | 73°F | 64°F | 2.11" | 0" |
| 2001 | 76°F | 57°F | 0" | 0" |
| 2000 | 81°F | 52°F | 0" | 0" |
| 1999 | 74°F | 47°F | 0" | 0" |
| 1998 | 77°F | 65°F | 0.46" | 0" |
| 1997 | 81°F | 59°F | 0.05" | 0" |
| 1996 | 72°F | 52°F | 0" | 0" |
| 1995 | 74°F | 50°F | 0" | 0" |
| 1994 | 80°F | 54°F | 0" | 0" |
| 1993 | 75°F | 51°F | 0" | 0" |
| 1992 | 84°F | 68°F | 0.13" | 0" |
| 1991 | 58°F | 43°F | 2.03" | 0" |
| 1990 | 69°F | 53°F | 1.96" | 0" |
| 1989 | 81°F | 49°F | 0" | 0" |
| 1988 | 89°F | 69°F | 0.58" | 0" |
| 1987 | 77°F | 50°F | 0" | 0" |
| 1986 | 72°F | 62°F | 4.29" | 0" |
| 1985 | 88°F | 55°F | 0" | 0" |
| 1982 | 84°F | 58°F | 1.55" | 0" |
| 1981 | 65°F | 42°F | 0" | 0" |
| 1980 | 67°F | 46°F | 0" | 0" |
| 1979 | 82°F | 54°F | 0" | 0" |
| 1978 | 93°F | 75°F | 0" | 0" |
| 1977 | 84°F | 60°F | 0" | 0" |
| 1976 | 81°F | 59°F | 0" | 0" |
| 1975 | 76°F | 58°F | 0" | 0" |
| 1974 | 80°F | 56°F | 0" | 0" |
| 1973 | 63°F | 47°F | 0" | 0" |
| 1972 | 98°F | 71°F | 0" | 0" |
| 1971 | 74°F | -- | 0.1" | 0" |