Weather on August 21
Saint Louis, MO
55 Years of Data
About This Date
August 21st in Saint Louis, MO typically brings warm summer weather, with average highs around 86°F and lows near 65°F. Over 52 years of records, the warmest August 21st was in 2003 (88°F average), while the coldest was 2004 (63°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 23% of August 21st dates historically, with the wettest August 21st recording 3.56" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for August 21st in Saint Louis, MO? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 81° | 66° | 73° | — | — |
| 2024 | 77° | 54° | 65° | — | — |
| 2023 | 96° | 77° | 87° | — | — |
| 2022 | 83° | 65° | 74° | — | — |
| 2021 | 88° | 73° | 80° | — | — |
| 2020 | 85° | 56° | 70° | — | — |
| 2019 | 89° | 69° | 79° | 1.88" | — |
| 2018 | 77° | 69° | 73° | 1.04" | — |
| 2017 | 90° | 74° | 82° | — | — |
| 2016 | 83° | 62° | 72° | — | — |
| 2015 | 82° | 62° | 72° | — | — |
| 2014 | 90° | 74° | 82° | 0.25" | — |
| 2013 | 89° | 69° | 79° | — | — |
| 2012 | 86° | 62° | 74° | — | — |
| 2011 | 89° | 69° | 79° | 0.36" | — |
| 2010 | 94° | 69° | 81° | 3.56" | — |
| 2009 | 80° | 63° | 71° | 0.05" | — |
| 2008 | 82° | 68° | 75° | 0.48" | — |
| 2007 | 83° | 75° | 79° | 0.25" | — |
| 2006 | 84° | 66° | 75° | — | — |
| 2005 | 92° | 72° | 82° | — | — |
| 2004coldest | 70° | 57° | 63° | 0.08" | — |
| 2003warmest | 98° | 78° | 88° | — | — |
| 2002 | 86° | 71° | 79° | — | — |
| 2001 | 83° | 64° | 73° | — | — |
| 2000 | 75° | 64° | 70° | — | — |
| 1999 | 80° | 57° | 69° | — | — |
| 1998 | 85° | 62° | 73° | — | — |
| 1997 | 78° | 59° | 69° | — | — |
| 1996 | 90° | 70° | 80° | — | — |
| 1995 | 86° | 72° | 79° | — | — |
| 1994 | 78° | 60° | 69° | — | — |
| 1993 | 85° | 67° | 76° | — | — |
| 1992 | 82° | 57° | 70° | — | — |
| 1991 | 88° | 66° | 77° | — | — |
| 1990 | 91° | 69° | 80° | — | — |
| 1989 | 82° | 70° | 76° | — | — |
| 1988 | 92° | 69° | 80° | — | — |
| 1987 | 100° | 60° | 80° | 0.84" | — |
| 1986 | 88° | 62° | 75° | — | — |
| 1985 | 81° | 61° | 71° | — | — |
| 1981 | 80° | 61° | 70° | — | — |
| 1980 | 90° | — | — | — | — |
| 1979 | 95° | 67° | 81° | — | — |
| 1978 | 85° | 50° | 67° | — | — |
| 1977 | 85° | 65° | 75° | 0.76" | — |
| 1976 | 88° | 60° | 74° | — | — |
| 1975 | 91° | 67° | 79° | — | — |
| 1974 | 91° | 62° | 77° | — | — |
| 1973 | 90° | 57° | 73° | — | — |
| 1972 | 100° | 72° | 86° | 0.03" | — |
| 1971 | 90° | 67° | 78° | — | — |
Saint Louis, MO Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Saint Louis, MO Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Saint Louis, MO Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Saint Louis, MO
Saint Louis, MO has no months that meet our "pleasant" threshold — every season has tradeoffs.