September weather in Union, OR
The average temperature in Union in September is 59.8°F (42.6°F–77.1°F). Average precipitation: 0.70 inches.
September is a fall month in Union, and is warmer than the annual average of 49°F. Daily temperatures swing about 34.5°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
77.1°F
Avg Low
42.6°F
Precipitation
0.70 in
Daylight
12h 18m
September records in Union
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 97.0°F (1950) | 32.0°F (1913) | 0.65 in (1984) |
| September 2 | 100.9°F (1950) | 33.1°F (2008) | 0.43 in (1941) |
| September 3 | 97.0°F (2007) | 28.9°F (1932) | 0.30 in (1941) |
| September 4 | 99.0°F (2003) | 33.1°F (1965) | 0.79 in (1940) |
| September 5 | 99.0°F (1955) | 30.9°F (1921) | 0.42 in (2007) |
| September 6 | 97.0°F (1988) | 30.9°F (1948) | 0.36 in (1927) |
| September 7 | 95.0°F (2003) | 26.1°F (1992) | 0.76 in (1926) |
| September 8 | 96.1°F (1990) | 30.9°F (1922) | 0.78 in (1970) |
| September 9 | 93.9°F (1981) | 27.0°F (1945) | 0.57 in (2019) |
| September 10 | 95.0°F (1948) | 28.0°F (1913) | 0.28 in (2019) |
| September 11 | 95.0°F (1990) | 30.0°F (2005) | 0.65 in (1927) |
| September 12 | 93.0°F (1990) | 27.0°F (1921) | 0.80 in (1928) |
| September 13 | 91.9°F (1948) | 23.0°F (1921) | 1.00 in (1980) |
| September 14 | 90.0°F (1945) | 25.0°F (1921) | 0.84 in (1955) |
| September 15 | 93.9°F (2000) | 26.1°F (1970) | 0.83 in (1959) |
| September 16 | 91.9°F (1951) | 25.0°F (1936) | 0.36 in (1963) |
| September 17 | 93.9°F (1981) | 24.1°F (1965) | 0.26 in (1963) |
| September 18 | 96.1°F (1981) | 23.0°F (1965) | 0.88 in (1989) |
| September 19 | 95.0°F (1981) | 24.1°F (1945) | 0.45 in (2017) |
| September 20 | 89.1°F (1939) | 26.1°F (1983) | 0.46 in (1977) |
| September 21 | 89.1°F (1938) | 26.1°F (1932) | 0.69 in (1945) |
| September 22 | 91.0°F (1967) | 21.0°F (1991) | 0.34 in (1917) |
| September 23 | 93.0°F (1966) | 24.1°F (1996) | 2.01 in (1917) |
| September 24 | 93.0°F (2009) | 18.0°F (1926) | 0.34 in (1973) |
| September 25 | 91.9°F (1952) | 19.9°F (1926) | 0.49 in (1973) |
| September 26 | 89.1°F (1962) | 25.0°F (1926) | 0.70 in (1959) |
| September 27 | 90.0°F (1963) | 26.1°F (1926) | 0.39 in (1988) |
| September 28 | 96.1°F (1913) | 23.0°F (1946) | 0.48 in (1981) |
| September 29 | 91.9°F (1963) | 24.1°F (1985) | 0.69 in (1927) |
| September 30 | 90.0°F (1963) | 21.9°F (1954) | 0.36 in (1951) |