September weather in Monmouth, OR
The average temperature in Monmouth in September is 63.4°F (49.1°F–77.6°F). Average precipitation: 1.60 inches.
September is a fall month in Monmouth, and is warmer than the annual average of 53.1°F. Daily temperatures swing about 28.5°F between overnight low and afternoon high. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
77.6°F
Avg Low
49.1°F
Precipitation
1.60 in
Daylight
12h 18m
September records in Monmouth
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.0°F (1987) | 36.0°F (1973) | 0.90 in (1971) |
| September 2 | 102.9°F (1988) | 37.0°F (1956) | 1.25 in (1979) |
| September 3 | 97.0°F (2017) | 39.0°F (1980) | 0.54 in (1979) |
| September 4 | 99.0°F (1955) | 41.0°F (1948) | 1.20 in (1945) |
| September 5 | 97.0°F (1955) | 37.0°F (1969) | 0.99 in (1938) |
| September 6 | 104.0°F (1944) | 37.0°F (1947) | 0.87 in (2013) |
| September 7 | 100.9°F (1981) | 37.0°F (1960) | 0.54 in (1947) |
| September 8 | 100.0°F (1981) | 36.0°F (1936) | 0.20 in (1952) |
| September 9 | 97.0°F (1944) | 37.0°F (1936) | 0.70 in (1949) |
| September 10 | 98.1°F (1944) | 32.0°F (1936) | 0.67 in (1978) |
| September 11 | 99.0°F (1944) | 33.1°F (1936) | 0.62 in (2018) |
| September 12 | 93.9°F (1975) | 35.1°F (1936) | 0.51 in (1941) |
| September 13 | 93.9°F (1951) | 36.0°F (1970) | 0.65 in (1978) |
| September 14 | 95.0°F (1957) | 30.9°F (1970) | 0.83 in (1985) |
| September 15 | 98.1°F (1937) | 34.0°F (1936) | 0.89 in (1997) |
| September 16 | 96.1°F (1981) | 35.1°F (1936) | 1.18 in (1946) |
| September 17 | 93.9°F (1951) | 33.1°F (1965) | 0.67 in (1997) |
| September 18 | 93.0°F (1938) | 33.1°F (1988) | 1.42 in (1969) |
| September 19 | 95.0°F (1974) | 34.0°F (1947) | 0.89 in (1959) |
| September 20 | 96.1°F (1952) | 34.0°F (1947) | 0.87 in (1982) |
| September 21 | 96.1°F (1952) | 32.0°F (1968) | 0.78 in (1972) |
| September 22 | 95.0°F (1947) | 35.1°F (1961) | 0.57 in (2013) |
| September 23 | 93.9°F (1974) | 34.0°F (1937) | 0.51 in (1948) |
| September 24 | 97.0°F (1974) | 34.0°F (1984) | 0.85 in (2014) |
| September 25 | 95.0°F (1974) | 32.0°F (1948) | 1.56 in (2023) |
| September 26 | 95.0°F (1967) | 32.0°F (1961) | 0.98 in (1981) |
| September 27 | 96.1°F (2003) | 30.9°F (1972) | 0.83 in (1995) |
| September 28 | 95.0°F (2003) | 34.0°F (1965) | 1.40 in (1962) |
| September 29 | 90.0°F (1936) | 30.9°F (1948) | 3.51 in (2013) |
| September 30 | 90.0°F (1975) | 30.0°F (1971) | 1.31 in (2013) |