September weather in West Richland, WA
The average temperature in West Richland in September is 65.2°F (51.4°F–78.9°F). Average precipitation: 0.29 inches.
September is a fall month in West Richland, and is warmer than the annual average of 53.6°F. Daily temperatures swing about 27.5°F between overnight low and afternoon high. Expect about 3 days with precipitation. Daylight averages about 12h 19m. For travel, September is one of the best months of the year to visit.
Avg High
78.9°F
Avg Low
51.4°F
Precipitation
0.29 in
Daylight
12h 19m
September records in West Richland
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (2020) | 44.1°F (1973) | 0.31 in (1961) |
| September 2 | 104.0°F (1950) | 44.1°F (1999) | 0.70 in (1971) |
| September 3 | 106.0°F (1950) | 45.0°F (1958) | 0.20 in (1997) |
| September 4 | 100.9°F (1955) | 43.0°F (1969) | 0.23 in (2000) |
| September 5 | 99.0°F (1955) | 43.0°F (1956) | 0.23 in (2009) |
| September 6 | 102.9°F (2020) | 42.1°F (1969) | 0.32 in (1947) |
| September 7 | 102.0°F (1944) | 43.0°F (1960) | 0.30 in (1946) |
| September 8 | 100.0°F (1958) | 39.9°F (1976) | 0.29 in (2003) |
| September 9 | 97.0°F (1944) | 39.9°F (1962) | 0.05 in (2025) |
| September 10 | 97.0°F (1944) | 39.9°F (1970) | 0.33 in (2000) |
| September 11 | 99.0°F (1944) | 42.1°F (1988) | 0.12 in (1985) |
| September 12 | 98.1°F (1973) | 39.9°F (2012) | 0.05 in (1982) |
| September 13 | 97.0°F (1948) | 39.9°F (1949) | 0.15 in (2004) |
| September 14 | 100.0°F (1948) | 37.9°F (1970) | 0.07 in (2025) |
| September 15 | 95.0°F (1957) | 35.1°F (1970) | 0.36 in (1959) |
| September 16 | 96.1°F (1953) | 37.0°F (1970) | 0.33 in (1954) |
| September 17 | 95.0°F (1967) | 32.0°F (1965) | 0.19 in (1947) |
| September 18 | 95.0°F (1952) | 37.0°F (1944) | 0.36 in (2010) |
| September 19 | 96.1°F (1951) | 37.0°F (1983) | 0.32 in (2010) |
| September 20 | 93.9°F (1952) | 33.1°F (1983) | 0.23 in (1973) |
| September 21 | 95.0°F (1952) | 37.0°F (1971) | 0.18 in (2017) |
| September 22 | 98.1°F (1967) | 36.0°F (1993) | 0.22 in (1984) |
| September 23 | 93.0°F (1950) | 32.0°F (2000) | 0.60 in (2020) |
| September 24 | 93.9°F (1952) | 32.0°F (2000) | 0.20 in (1992) |
| September 25 | 96.1°F (1952) | 30.9°F (1972) | 0.12 in (1998) |
| September 26 | 99.0°F (1952) | 30.9°F (1972) | 0.18 in (1959) |
| September 27 | 96.1°F (1952) | 30.9°F (1972) | 0.53 in (1981) |
| September 28 | 91.9°F (1949) | 30.9°F (1972) | 0.33 in (1957) |
| September 29 | 91.0°F (1963) | 30.9°F (1983) | 0.17 in (1986) |
| September 30 | 91.0°F (1976) | 30.9°F (1984) | 0.57 in (2005) |