August weather in LaSalle, IL
The average temperature in LaSalle in August is 71.5°F (60.8°F–82.2°F). Average precipitation: 3.70 inches.
August is a summer month in LaSalle, and is warmer than the annual average of 49.6°F. Daily temperatures swing about 21.4°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 40m. For travel, August is a comfortable month to visit.
Avg High
82.2°F
Avg Low
60.8°F
Precipitation
3.70 in
Daylight
13h 40m
August records in LaSalle
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 100.9°F (2006) | 50.0°F (1976) | 1.20 in (1975) |
| August 2 | 102.0°F (1988) | 52.0°F (1976) | 1.05 in (1981) |
| August 3 | 100.9°F (1988) | 43.0°F (1976) | 1.42 in (2006) |
| August 4 | 100.0°F (1988) | 45.0°F (1972) | 1.76 in (2004) |
| August 5 | 97.0°F (1988) | 46.9°F (1972) | 1.50 in (1980) |
| August 6 | 96.1°F (1968) | 45.0°F (1994) | 1.39 in (1972) |
| August 7 | 96.1°F (1968) | 46.0°F (1989) | 0.80 in (1972) |
| August 8 | 97.0°F (1980) | 48.0°F (1975) | 1.33 in (1991) |
| August 9 | 100.0°F (1988) | 42.1°F (1976) | 2.20 in (2011) |
| August 10 | 97.0°F (2005) | 46.9°F (1972) | 1.75 in (1995) |
| August 11 | 95.0°F (1983) | 46.0°F (1968) | 2.38 in (2006) |
| August 12 | 96.1°F (1988) | 43.0°F (1967) | 0.73 in (2003) |
| August 13 | 95.0°F (1988) | 45.0°F (2004) | 1.40 in (1990) |
| August 14 | 93.9°F (1995) | 46.0°F (2004) | 3.10 in (1984) |
| August 15 | 96.1°F (1988) | 45.0°F (1992) | 3.85 in (1981) |
| August 16 | 99.0°F (1988) | 46.0°F (2004) | 1.25 in (1980) |
| August 17 | 102.9°F (1988) | 45.0°F (1992) | 1.06 in (1968) |
| August 18 | 102.0°F (1988) | 44.1°F (1963) | 3.71 in (1979) |
| August 19 | 100.0°F (1988) | 48.9°F (2012) | 1.64 in (1994) |
| August 20 | 100.0°F (1983) | 46.0°F (1992) | 4.50 in (1979) |
| August 21 | 98.1°F (1983) | 45.0°F (1992) | 0.90 in (1987) |
| August 22 | 98.1°F (2003) | 48.0°F (1969) | 1.20 in (2008) |
| August 23 | 96.1°F (1975) | 46.9°F (1984) | 1.16 in (1972) |
| August 24 | 99.0°F (2023) | 46.9°F (1987) | 4.22 in (2007) |
| August 25 | 98.1°F (2023) | 48.9°F (2025) | 0.55 in (2004) |
| August 26 | 97.0°F (2003) | 46.9°F (1964) | 2.93 in (1987) |
| August 27 | 97.0°F (1973) | 46.9°F (2025) | 3.10 in (1983) |
| August 28 | 96.1°F (2024) | 39.9°F (1986) | 3.02 in (2009) |
| August 29 | 96.1°F (1991) | 41.0°F (1986) | 2.40 in (2006) |
| August 30 | 96.1°F (2003) | 46.9°F (1967) | 3.05 in (1975) |
| August 31 | 93.9°F (2013) | 41.0°F (1967) | 1.37 in (1980) |