September weather in Hamilton, WA
The average temperature in Hamilton in September is 59.4°F (49.3°F–69.5°F). Average precipitation: 2.86 inches.
September is a fall month in Hamilton, and is warmer than the annual average of 51.3°F. Daily temperatures swing about 20.2°F between overnight low and afternoon high. Expect about 12 days with precipitation. Daylight averages about 12h 20m. For travel, September is a comfortable month to visit.
Avg High
69.5°F
Avg Low
49.3°F
Precipitation
2.86 in
Daylight
12h 20m
September records in Hamilton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 90.0°F (1918) | 39.0°F (1960) | 3.29 in (2016) |
| September 2 | 87.1°F (1918) | 37.9°F (1919) | 1.64 in (1980) |
| September 3 | 87.1°F (1974) | 37.0°F (1903) | 1.97 in (2014) |
| September 4 | 89.1°F (1988) | 39.0°F (1952) | 1.01 in (1913) |
| September 5 | 91.0°F (1944) | 37.0°F (1956) | 1.92 in (1931) |
| September 6 | 89.1°F (1973) | 37.9°F (1905) | 1.78 in (1984) |
| September 7 | 89.1°F (1949) | 36.0°F (1896) | 1.86 in (1906) |
| September 8 | 88.0°F (1981) | 35.1°F (1896) | 1.70 in (1914) |
| September 9 | 84.9°F (1898) | 34.0°F (1901) | 1.31 in (1903) |
| September 10 | 88.0°F (1946) | 33.1°F (2006) | 1.02 in (2018) |
| September 11 | 84.9°F (1901) | 35.1°F (1902) | 1.64 in (1920) |
| September 12 | 90.0°F (1924) | 34.0°F (1896) | 1.07 in (1906) |
| September 13 | 84.9°F (1961) | 32.0°F (1896) | 1.50 in (1963) |
| September 14 | 89.1°F (1951) | 34.0°F (1896) | 1.60 in (1935) |
| September 15 | 89.1°F (1979) | 34.0°F (1901) | 1.53 in (1996) |
| September 16 | 86.0°F (1967) | 32.0°F (1908) | 1.34 in (1990) |
| September 17 | 88.0°F (1967) | 32.0°F (1908) | 1.63 in (1964) |
| September 18 | 84.0°F (1897) | 30.9°F (1908) | 1.86 in (2021) |
| September 19 | 89.1°F (1901) | 35.1°F (1904) | 1.55 in (1932) |
| September 20 | 82.9°F (1951) | 34.0°F (1902) | 1.48 in (1980) |
| September 21 | 89.1°F (1952) | 35.1°F (1902) | 1.14 in (1972) |
| September 22 | 84.0°F (1952) | 34.0°F (1908) | 1.36 in (1984) |
| September 23 | 84.0°F (1975) | 30.0°F (1926) | 1.05 in (1972) |
| September 24 | 89.1°F (1943) | 30.9°F (1948) | 1.90 in (1959) |
| September 25 | 84.0°F (1974) | 28.0°F (1908) | 0.97 in (1951) |
| September 26 | 80.1°F (1974) | 28.0°F (1912) | 1.55 in (2024) |
| September 27 | 82.9°F (1963) | 30.0°F (1972) | 1.47 in (1930) |
| September 28 | 86.0°F (1918) | 28.9°F (1919) | 1.37 in (1962) |
| September 29 | 87.1°F (2017) | 28.9°F (1901) | 1.61 in (2013) |
| September 30 | 82.0°F (1992) | 32.0°F (1901) | 1.80 in (2005) |