September weather in Rainier, OR
The average temperature in Rainier in September is 62.6°F (49.6°F–75.7°F). Average precipitation: 2.29 inches.
September is a fall month in Rainier, and is warmer than the annual average of 53.2°F. Daily temperatures swing about 26.1°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
75.7°F
Avg Low
49.6°F
Precipitation
2.29 in
Daylight
12h 18m
September records in Rainier
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 99.0°F (1987) | 39.0°F (1973) | 1.24 in (1936) |
| September 2 | 96.1°F (2017) | 39.0°F (1932) | 0.73 in (1961) |
| September 3 | 100.0°F (1988) | 37.0°F (1932) | 1.27 in (1945) |
| September 4 | 98.1°F (2003) | 41.0°F (1929) | 0.78 in (1938) |
| September 5 | 104.0°F (1944) | 39.9°F (1947) | 1.18 in (1959) |
| September 6 | 97.0°F (2024) | 34.0°F (1929) | 1.05 in (1931) |
| September 7 | 95.0°F (1935) | 35.1°F (1929) | 0.88 in (1984) |
| September 8 | 100.0°F (1981) | 36.0°F (1929) | 0.99 in (1978) |
| September 9 | 91.0°F (1999) | 37.9°F (1936) | 0.73 in (1940) |
| September 10 | 98.1°F (1944) | 36.0°F (1936) | 1.04 in (1985) |
| September 11 | 91.0°F (1948) | 32.0°F (1936) | 0.76 in (1962) |
| September 12 | 90.0°F (1929) | 37.0°F (1932) | 0.55 in (1934) |
| September 13 | 93.0°F (1999) | 34.0°F (1970) | 0.50 in (1941) |
| September 14 | 93.9°F (1937) | 34.0°F (1970) | 2.47 in (1935) |
| September 15 | 93.0°F (1979) | 34.0°F (1936) | 0.81 in (1996) |
| September 16 | 97.0°F (1967) | 36.0°F (2021) | 0.69 in (1949) |
| September 17 | 91.0°F (2025) | 33.1°F (1965) | 0.66 in (1958) |
| September 18 | 87.1°F (1952) | 33.1°F (1942) | 1.10 in (2021) |
| September 19 | 89.1°F (1991) | 30.0°F (1928) | 1.39 in (1988) |
| September 20 | 93.0°F (1952) | 37.0°F (1947) | 1.36 in (2017) |
| September 21 | 95.0°F (1952) | 33.1°F (1937) | 1.15 in (1972) |
| September 22 | 93.9°F (1950) | 34.0°F (1932) | 0.86 in (1934) |
| September 23 | 93.9°F (1990) | 34.0°F (1931) | 1.24 in (1948) |
| September 24 | 93.0°F (1943) | 28.9°F (1926) | 1.32 in (1986) |
| September 25 | 90.0°F (1974) | 30.0°F (1926) | 0.65 in (1977) |
| September 26 | 91.0°F (1991) | 28.9°F (1926) | 1.03 in (1950) |
| September 27 | 88.0°F (2000) | 32.0°F (1926) | 1.54 in (1927) |
| September 28 | 90.0°F (1967) | 32.0°F (1929) | 0.84 in (1962) |
| September 29 | 86.0°F (2017) | 32.0°F (1930) | 0.80 in (1927) |
| September 30 | 87.1°F (1993) | 32.0°F (1950) | 1.07 in (2002) |