September weather in Forest Grove, OR
The average temperature in Forest Grove in September is 62.4°F (48.7°F–76.1°F). Average precipitation: 1.34 inches.
September is a fall month in Forest Grove, and is warmer than the annual average of 52.1°F. Daily temperatures swing about 27.4°F between overnight low and afternoon high. Expect about 5 days with precipitation. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
76.1°F
Avg Low
48.7°F
Precipitation
1.34 in
Daylight
12h 18m
September records in Forest Grove
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.9°F (1987) | 35.1°F (1919) | 1.17 in (1941) |
| September 2 | 99.0°F (1998) | 37.0°F (1960) | 0.80 in (1979) |
| September 3 | 104.0°F (1988) | 39.0°F (1932) | 1.00 in (1979) |
| September 4 | 99.0°F (1955) | 39.0°F (1952) | 2.02 in (1945) |
| September 5 | 100.9°F (1944) | 37.9°F (1947) | 0.95 in (1919) |
| September 6 | 104.0°F (1953) | 37.9°F (1905) | 0.79 in (1931) |
| September 7 | 98.1°F (1958) | 36.0°F (1896) | 0.65 in (2009) |
| September 8 | 100.0°F (1981) | 36.0°F (1927) | 0.48 in (1978) |
| September 9 | 98.1°F (1993) | 35.1°F (1928) | 0.74 in (1931) |
| September 10 | 96.1°F (1944) | 35.1°F (1906) | 0.57 in (1956) |
| September 11 | 96.1°F (1993) | 32.0°F (1906) | 0.63 in (1919) |
| September 12 | 98.1°F (2013) | 33.1°F (1921) | 0.77 in (1920) |
| September 13 | 91.9°F (1957) | 32.0°F (1921) | 1.09 in (1920) |
| September 14 | 97.0°F (1937) | 36.0°F (1927) | 1.59 in (1935) |
| September 15 | 96.1°F (1995) | 34.0°F (1936) | 1.50 in (1996) |
| September 16 | 97.0°F (1981) | 37.0°F (1896) | 0.58 in (1986) |
| September 17 | 93.9°F (1951) | 30.0°F (1965) | 0.68 in (1969) |
| September 18 | 97.0°F (1999) | 30.0°F (1904) | 1.09 in (1921) |
| September 19 | 97.0°F (1999) | 32.0°F (1928) | 0.62 in (1977) |
| September 20 | 96.1°F (1999) | 35.1°F (1897) | 0.73 in (2017) |
| September 21 | 96.1°F (1952) | 33.1°F (1955) | 1.04 in (1972) |
| September 22 | 96.1°F (1974) | 34.0°F (1893) | 0.55 in (1973) |
| September 23 | 96.1°F (1952) | 33.1°F (1896) | 1.04 in (1920) |
| September 24 | 96.1°F (1974) | 28.9°F (1906) | 0.99 in (2014) |
| September 25 | 96.1°F (1974) | 27.0°F (1908) | 0.77 in (2023) |
| September 26 | 93.0°F (1967) | 27.0°F (1908) | 0.68 in (1997) |
| September 27 | 95.0°F (1967) | 32.0°F (1929) | 1.50 in (1940) |
| September 28 | 95.0°F (1967) | 30.0°F (1897) | 1.08 in (1962) |
| September 29 | 89.1°F (1989) | 33.1°F (1919) | 1.43 in (1925) |
| September 30 | 93.9°F (1993) | 30.0°F (1903) | 4.23 in (2013) |