August weather in Rock Island, WA
The average temperature in Rock Island in August is 73.7°F (61.0°F–86.4°F). Average precipitation: 0.23 inches.
August is a summer month in Rock Island, and is warmer than the annual average of 51.2°F. Daily temperatures swing about 25.4°F between overnight low and afternoon high. Expect about 2 days with precipitation. Daylight averages about 14h 4m. For travel, August is a comfortable month to visit.
Avg High
86.4°F
Avg Low
61.0°F
Precipitation
0.23 in
Daylight
14h 4m
August records in Rock Island
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 107.1°F (2009) | 51.1°F (1987) | 1.09 in (2013) |
| August 2 | 102.9°F (1961) | 48.0°F (1964) | 0.02 in (2013) |
| August 3 | 107.1°F (1961) | 52.0°F (2002) | 0.76 in (1962) |
| August 4 | 109.0°F (1961) | 53.1°F (1962) | 0.11 in (2004) |
| August 5 | 102.0°F (1997) | 45.0°F (1969) | 0.20 in (2004) |
| August 6 | 102.9°F (1972) | 50.0°F (2002) | 0.96 in (1976) |
| August 7 | 102.9°F (1972) | 52.0°F (1984) | 0.47 in (1976) |
| August 8 | 104.0°F (1971) | 53.1°F (1970) | 0.02 in (1994) |
| August 9 | 104.0°F (1971) | 50.0°F (1995) | 0.22 in (2019) |
| August 10 | 104.0°F (1971) | 53.1°F (1964) | 0.29 in (2013) |
| August 11 | 104.0°F (1971) | 53.1°F (1966) | 0.47 in (1983) |
| August 12 | 102.9°F (2015) | 53.1°F (1991) | 0.27 in (2014) |
| August 13 | 102.0°F (1977) | 48.0°F (1995) | 0.06 in (2017) |
| August 14 | 102.0°F (1992) | 48.9°F (1982) | 0.51 in (2014) |
| August 15 | 104.0°F (2023) | 48.9°F (1960) | 0.43 in (1961) |
| August 16 | 102.9°F (1967) | 48.9°F (1995) | 0.08 in (1976) |
| August 17 | 104.0°F (2008) | 48.0°F (1998) | 0.03 in (1995) |
| August 18 | 104.0°F (1967) | 46.9°F (1995) | 1.51 in (1975) |
| August 19 | 102.9°F (1967) | 48.0°F (1973) | 0.15 in (1968) |
| August 20 | 102.0°F (1977) | 46.0°F (1968) | 0.31 in (1993) |
| August 21 | 100.0°F (2005) | 46.0°F (1960) | 0.34 in (1990) |
| August 22 | 100.0°F (1961) | 43.0°F (1960) | 0.22 in (2001) |
| August 23 | 100.9°F (1961) | 42.1°F (1992) | 0.90 in (1965) |
| August 24 | 100.0°F (2025) | 44.1°F (1992) | 0.30 in (1968) |
| August 25 | 100.9°F (2025) | 46.0°F (1992) | 0.15 in (1989) |
| August 26 | 95.0°F (1984) | 46.9°F (1976) | 0.33 in (1994) |
| August 27 | 96.1°F (1972) | 46.9°F (1960) | 0.39 in (1968) |
| August 28 | 99.0°F (1972) | 45.0°F (1980) | 0.12 in (1975) |
| August 29 | 100.0°F (1998) | 46.0°F (1980) | 0.32 in (1966) |
| August 30 | 97.0°F (1967) | 45.0°F (1965) | 0.42 in (1977) |
| August 31 | 99.0°F (1967) | 45.0°F (1999) | 0.05 in (1964) |