August weather in Lake St. Louis, MO
The average temperature in Lake St. Louis in August is 76.0°F (65.4°F–86.7°F). Average precipitation: 3.58 inches.
August is a summer month in Lake St. Louis, and is warmer than the annual average of 55.2°F. Daily temperatures swing about 21.3°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 13h 31m. For travel, August is a comfortable month to visit.
Avg High
86.7°F
Avg Low
65.4°F
Precipitation
3.58 in
Daylight
13h 31m
August records in Lake St. Louis
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 102.0°F (1970) | 52.0°F (1960) | 1.81 in (1979) |
| August 2 | 100.0°F (2012) | 51.1°F (1985) | 0.78 in (1993) |
| August 3 | 102.9°F (1987) | 51.1°F (1974) | 1.03 in (2016) |
| August 4 | 104.0°F (1964) | 48.9°F (1986) | 2.61 in (2022) |
| August 5 | 98.1°F (2010) | 52.0°F (1966) | 1.55 in (2016) |
| August 6 | 98.1°F (1963) | 51.1°F (1957) | 2.32 in (2015) |
| August 7 | 98.1°F (2006) | 50.0°F (1957) | 1.59 in (1999) |
| August 8 | 100.0°F (1984) | 44.1°F (1989) | 2.47 in (2014) |
| August 9 | 99.0°F (1988) | 45.0°F (1989) | 3.97 in (2020) |
| August 10 | 98.1°F (1963) | 50.0°F (1989) | 1.53 in (1966) |
| August 11 | 99.0°F (2010) | 46.9°F (1989) | 1.48 in (1980) |
| August 12 | 98.1°F (2005) | 46.0°F (1967) | 2.42 in (1993) |
| August 13 | 102.9°F (2007) | 44.1°F (1964) | 0.83 in (2021) |
| August 14 | 98.1°F (2010) | 48.9°F (2004) | 1.17 in (2005) |
| August 15 | 100.0°F (2007) | 46.0°F (1992) | 1.09 in (1997) |
| August 16 | 104.0°F (2007) | 45.0°F (1992) | 1.10 in (2005) |
| August 17 | 98.1°F (2025) | 50.0°F (1992) | 1.79 in (2017) |
| August 18 | 109.0°F (2000) | 52.0°F (1976) | 1.22 in (2009) |
| August 19 | 99.0°F (1972) | 48.0°F (1989) | 1.68 in (2007) |
| August 20 | 105.1°F (1962) | 46.0°F (1967) | 1.40 in (1964) |
| August 21 | 105.1°F (1962) | 48.9°F (1967) | 1.34 in (2010) |
| August 22 | 100.0°F (1983) | 52.0°F (1991) | 1.96 in (2008) |
| August 23 | 98.1°F (2023) | 48.9°F (1966) | 1.22 in (2015) |
| August 24 | 98.1°F (2012) | 48.0°F (1986) | 1.05 in (2001) |
| August 25 | 98.1°F (2023) | 46.0°F (1958) | 0.68 in (2018) |
| August 26 | 100.9°F (2023) | 50.0°F (1958) | 2.60 in (2019) |
| August 27 | 98.1°F (1973) | 46.0°F (1967) | 1.72 in (1981) |
| August 28 | 99.0°F (2024) | 41.0°F (1967) | 1.90 in (2009) |
| August 29 | 100.0°F (1984) | 36.0°F (1986) | 1.52 in (1977) |
| August 30 | 107.1°F (1984) | 39.0°F (1986) | 0.87 in (2003) |
| August 31 | 98.1°F (2013) | 45.0°F (1967) | 1.34 in (2016) |