September weather in Santa Rosa, CA
The average temperature in Santa Rosa in September is 67.5°F (51.0°F–83.9°F). Average precipitation: 0.15 inches.
September is a fall month in Santa Rosa, and is warmer than the annual average of 59°F. Daily temperatures swing about 32.9°F between overnight low and afternoon high. Expect about 1 days with precipitation. Daylight averages about 12h 14m. For travel, September is a comfortable month to visit.
Avg High
83.9°F
Avg Low
51.0°F
Precipitation
0.15 in
Daylight
12h 14m
September records in Santa Rosa
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 109.9°F (2017) | 36.0°F (1915) | 0.24 in (1983) |
| September 2 | 109.9°F (2017) | 34.0°F (1914) | 0.34 in (2000) |
| September 3 | 108.0°F (1955) | 34.0°F (1914) | 0.06 in (1912) |
| September 4 | 108.0°F (1955) | 34.0°F (1914) | 0.05 in (1907) |
| September 5 | 111.9°F (2022) | 34.0°F (1914) | 0.05 in (1952) |
| September 6 | 115.0°F (2022) | 32.0°F (1914) | 2.24 in (1912) |
| September 7 | 109.9°F (2020) | 34.0°F (1914) | 0.66 in (1912) |
| September 8 | 109.9°F (2020) | 34.0°F (1914) | 0.77 in (1985) |
| September 9 | 107.1°F (1944) | 32.0°F (1915) | 1.02 in (1978) |
| September 10 | 100.0°F (1914) | 32.0°F (1915) | 0.32 in (1978) |
| September 11 | 104.0°F (1979) | 30.0°F (1915) | 0.07 in (1976) |
| September 12 | 108.0°F (1979) | 30.0°F (1915) | 0.37 in (1940) |
| September 13 | 109.9°F (1971) | 30.0°F (1915) | 1.25 in (1918) |
| September 14 | 109.9°F (1971) | 32.0°F (1915) | 1.12 in (1918) |
| September 15 | 107.1°F (1971) | 32.0°F (1915) | 0.28 in (1955) |
| September 16 | 108.0°F (1913) | 32.0°F (1915) | 1.56 in (1989) |
| September 17 | 104.0°F (1913) | 34.0°F (1915) | 0.71 in (1925) |
| September 18 | 104.0°F (1913) | 32.0°F (1915) | 2.82 in (1959) |
| September 19 | 100.9°F (2000) | 30.0°F (1914) | 0.34 in (1959) |
| September 20 | 104.0°F (1939) | 32.0°F (1914) | 0.42 in (1973) |
| September 21 | 105.1°F (1939) | 32.0°F (1915) | 0.53 in (1923) |
| September 22 | 105.1°F (1939) | 30.0°F (1915) | 0.23 in (1973) |
| September 23 | 105.1°F (1939) | 30.0°F (1915) | 2.90 in (1904) |
| September 24 | 102.0°F (1936) | 34.0°F (1914) | 0.55 in (1986) |
| September 25 | 104.0°F (1964) | 32.0°F (1914) | 0.68 in (1909) |
| September 26 | 102.9°F (2009) | 30.0°F (1915) | 0.56 in (1972) |
| September 27 | 102.9°F (1963) | 30.0°F (1915) | 1.50 in (1957) |
| September 28 | 104.0°F (2010) | 30.0°F (1914) | 0.48 in (1976) |
| September 29 | 104.0°F (1966) | 30.0°F (1914) | 0.56 in (1989) |
| September 30 | 102.0°F (1980) | 32.0°F (1914) | 0.25 in (1919) |