August weather in Janesville, IA
The average temperature in Janesville in August is 71.9°F (61.0°F–82.9°F). Average precipitation: 4.17 inches.
August is a summer month in Janesville, and is warmer than the annual average of 49°F. Daily temperatures swing about 21.9°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 13h 44m. For travel, August is a comfortable month to visit.
Avg High
82.9°F
Avg Low
61.0°F
Precipitation
4.17 in
Daylight
13h 44m
August records in Janesville
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 100.9°F (1988) | 48.9°F (1977) | 1.23 in (1972) |
| August 2 | 100.9°F (1988) | 48.9°F (1965) | 0.72 in (1959) |
| August 3 | 100.0°F (1988) | 48.9°F (1971) | 1.27 in (2004) |
| August 4 | 97.0°F (1989) | 45.0°F (1978) | 2.13 in (1968) |
| August 5 | 93.0°F (1965) | 44.1°F (1994) | 3.33 in (1998) |
| August 6 | 95.0°F (2022) | 45.0°F (2012) | 1.81 in (2018) |
| August 7 | 99.0°F (1988) | 46.0°F (1989) | 3.62 in (1991) |
| August 8 | 93.9°F (1983) | 45.0°F (1976) | 2.47 in (1968) |
| August 9 | 95.0°F (1985) | 46.0°F (1972) | 1.16 in (1980) |
| August 10 | 96.1°F (1983) | 48.9°F (1967) | 1.93 in (2025) |
| August 11 | 96.1°F (1988) | 43.0°F (1982) | 1.44 in (2016) |
| August 12 | 93.9°F (1995) | 45.0°F (1964) | 1.41 in (2002) |
| August 13 | 95.0°F (1965) | 41.0°F (1964) | 1.76 in (1957) |
| August 14 | 100.9°F (1988) | 39.0°F (1964) | 0.89 in (1993) |
| August 15 | 104.0°F (1988) | 42.1°F (2004) | 2.13 in (1977) |
| August 16 | 102.9°F (1988) | 43.0°F (1976) | 1.94 in (1965) |
| August 17 | 105.1°F (1988) | 46.0°F (1962) | 1.22 in (1998) |
| August 18 | 98.1°F (1983) | 43.0°F (1977) | 1.91 in (1954) |
| August 19 | 100.0°F (1983) | 42.1°F (1963) | 2.75 in (2007) |
| August 20 | 98.1°F (2003) | 33.1°F (1950) | 4.92 in (1966) |
| August 21 | 97.0°F (1955) | 39.0°F (2004) | 0.76 in (1951) |
| August 22 | 99.0°F (2023) | 46.9°F (1951) | 1.63 in (1988) |
| August 23 | 105.1°F (2023) | 45.0°F (1969) | 2.34 in (1997) |
| August 24 | 102.9°F (2023) | 44.1°F (1977) | 1.80 in (2021) |
| August 25 | 98.1°F (2003) | 39.9°F (1958) | 2.94 in (1994) |
| August 26 | 98.1°F (2024) | 42.1°F (1964) | 2.90 in (1978) |
| August 27 | 96.1°F (1955) | 41.0°F (1971) | 0.98 in (1998) |
| August 28 | 97.0°F (1955) | 39.9°F (1986) | 4.10 in (2015) |
| August 29 | 98.1°F (1984) | 41.0°F (1988) | 2.87 in (1993) |
| August 30 | 96.1°F (2012) | 44.1°F (1974) | 1.75 in (1956) |
| August 31 | 99.0°F (2000) | 37.9°F (1967) | 1.96 in (2010) |