August weather in Alton, MO
The average temperature in Alton in August is 76.1°F (64.2°F–88.1°F). Average precipitation: 3.92 inches.
August is a summer month in Alton, and is warmer than the annual average of 55.7°F. Daily temperatures swing about 23.9°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 13h 24m. For travel, August is hot.
Avg High
88.1°F
Avg Low
64.2°F
Precipitation
3.92 in
Daylight
13h 24m
August records in Alton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 97.0°F (1964) | 48.0°F (1971) | 2.00 in (1970) |
| August 2 | 99.0°F (1964) | 45.0°F (1973) | 1.85 in (1967) |
| August 3 | 102.9°F (1964) | 50.0°F (1973) | 1.65 in (1961) |
| August 4 | 109.0°F (2011) | 46.9°F (1974) | 1.36 in (2022) |
| August 5 | 100.0°F (1983) | 48.9°F (1974) | 1.02 in (1994) |
| August 6 | 98.1°F (2007) | 50.0°F (1994) | 2.00 in (2013) |
| August 7 | 100.9°F (2011) | 52.0°F (1969) | 1.34 in (2013) |
| August 8 | 100.9°F (1999) | 51.1°F (2004) | 1.60 in (1949) |
| August 9 | 102.9°F (1969) | 51.1°F (2004) | 3.40 in (1970) |
| August 10 | 100.0°F (1969) | 50.0°F (1976) | 1.87 in (2023) |
| August 11 | 100.9°F (1999) | 53.1°F (1969) | 1.60 in (1940) |
| August 12 | 100.9°F (2007) | 50.0°F (2004) | 1.74 in (2017) |
| August 13 | 102.9°F (2007) | 46.9°F (1964) | 2.38 in (1977) |
| August 14 | 102.0°F (2007) | 46.9°F (2004) | 1.54 in (1977) |
| August 15 | 100.9°F (2007) | 50.0°F (1994) | 2.54 in (1964) |
| August 16 | 102.9°F (2007) | 48.9°F (2004) | 1.90 in (1981) |
| August 17 | 100.9°F (2000) | 51.1°F (1994) | 1.58 in (1977) |
| August 18 | 104.0°F (2000) | 52.0°F (1976) | 1.78 in (1974) |
| August 19 | 102.0°F (1999) | 51.1°F (1976) | 1.27 in (1960) |
| August 20 | 100.9°F (2006) | 46.9°F (1967) | 2.08 in (2009) |
| August 21 | 99.0°F (1983) | 46.9°F (1967) | 1.54 in (1969) |
| August 22 | 99.0°F (2023) | 51.1°F (1978) | 1.57 in (2005) |
| August 23 | 99.0°F (2000) | 50.0°F (1978) | 4.20 in (2019) |
| August 24 | 102.0°F (1978) | 52.0°F (1997) | 0.74 in (1977) |
| August 25 | 102.9°F (1983) | 52.0°F (2009) | 1.21 in (2011) |
| August 26 | 100.0°F (1983) | 52.0°F (2009) | 2.00 in (1964) |
| August 27 | 102.0°F (1983) | 48.0°F (2025) | 1.79 in (1941) |
| August 28 | 102.0°F (1963) | 48.9°F (1968) | 1.45 in (2020) |
| August 29 | 102.9°F (2000) | 46.0°F (1965) | 1.29 in (1977) |
| August 30 | 105.1°F (2000) | 48.9°F (1965) | 2.37 in (2022) |
| August 31 | 104.0°F (2000) | 48.0°F (1976) | 2.37 in (2003) |