September weather in Coulee Dam, WA
The average temperature in Coulee Dam in September is 63.7°F (50.5°F–76.8°F). Average precipitation: 0.36 inches.
September is a fall month in Coulee Dam, and is warmer than the annual average of 49.9°F. Daily temperatures swing about 26.3°F between overnight low and afternoon high. Expect about 4 days with precipitation. Daylight averages about 12h 20m. For travel, September is one of the best months of the year to visit.
Avg High
76.8°F
Avg Low
50.5°F
Precipitation
0.36 in
Daylight
12h 20m
September records in Coulee Dam
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (1938) | 39.0°F (1951) | 0.18 in (1981) |
| September 2 | 104.0°F (1938) | 39.9°F (1951) | 0.54 in (1941) |
| September 3 | 102.9°F (1988) | 37.9°F (1951) | 0.45 in (1997) |
| September 4 | 100.9°F (1988) | 37.0°F (1951) | 0.57 in (1960) |
| September 5 | 99.0°F (1934) | 39.9°F (1951) | 0.37 in (1937) |
| September 6 | 97.0°F (1944) | 37.9°F (1992) | 0.59 in (1971) |
| September 7 | 96.1°F (1944) | 36.0°F (1984) | 0.48 in (1947) |
| September 8 | 97.0°F (1935) | 39.9°F (1951) | 0.41 in (1978) |
| September 9 | 99.0°F (1935) | 39.9°F (1951) | 0.22 in (1952) |
| September 10 | 96.1°F (1935) | 42.1°F (1978) | 0.36 in (1941) |
| September 11 | 99.0°F (1940) | 39.0°F (1986) | 0.63 in (2021) |
| September 12 | 95.0°F (1937) | 37.9°F (1978) | 0.25 in (1934) |
| September 13 | 95.0°F (1937) | 30.9°F (1970) | 1.35 in (1980) |
| September 14 | 98.1°F (1938) | 5.0°F (2011) | 0.23 in (1985) |
| September 15 | 99.0°F (1938) | 39.9°F (1970) | 0.70 in (1959) |
| September 16 | 100.0°F (1938) | 34.0°F (1965) | 1.18 in (1963) |
| September 17 | 99.0°F (1938) | 35.1°F (1965) | 0.43 in (2019) |
| September 18 | 100.0°F (1938) | 34.0°F (2002) | 0.76 in (1986) |
| September 19 | 93.9°F (1950) | 37.9°F (1957) | 0.44 in (2010) |
| September 20 | 96.1°F (1939) | 36.0°F (1983) | 0.39 in (1945) |
| September 21 | 96.1°F (1950) | 37.9°F (1970) | 0.20 in (2008) |
| September 22 | 93.9°F (1938) | 35.1°F (1970) | 0.65 in (1934) |
| September 23 | 91.0°F (1939) | 30.0°F (1970) | 0.86 in (1986) |
| September 24 | 90.0°F (1952) | 32.0°F (2000) | 0.32 in (2020) |
| September 25 | 93.9°F (1952) | 32.0°F (1972) | 0.27 in (2014) |
| September 26 | 89.1°F (1950) | 37.0°F (1945) | 1.38 in (1948) |
| September 27 | 89.1°F (1950) | 33.1°F (1972) | 0.61 in (1940) |
| September 28 | 89.1°F (1950) | 34.0°F (1983) | 0.59 in (1962) |
| September 29 | 90.0°F (1935) | 30.0°F (1982) | 0.25 in (1944) |
| September 30 | 91.9°F (1935) | 30.0°F (1974) | 0.53 in (1951) |