September weather in Petaluma, CA
The average temperature in Petaluma in September is 66.5°F (51.4°F–81.6°F). Average precipitation: 0.09 inches.
September is a fall month in Petaluma, and is warmer than the annual average of 58°F. Daily temperatures swing about 30.2°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
81.6°F
Avg Low
51.4°F
Precipitation
0.09 in
Daylight
12h 14m
September records in Petaluma
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 107.1°F (2017) | 39.9°F (2011) | 0.05 in (1983) |
| September 2 | 107.1°F (1955) | 39.0°F (1965) | 0.13 in (2000) |
| September 3 | 108.0°F (1955) | 39.0°F (1919) | 0.01 in (2003) |
| September 4 | 100.0°F (1975) | 39.0°F (1948) | 0.00 in (1894) |
| September 5 | 108.0°F (2022) | 37.0°F (1948) | 0.04 in (1978) |
| September 6 | 109.0°F (2022) | 44.1°F (1914) | 0.14 in (1930) |
| September 7 | 105.1°F (1957) | 43.0°F (1960) | 0.08 in (1925) |
| September 8 | 102.9°F (1984) | 44.1°F (1915) | 0.15 in (1919) |
| September 9 | 108.0°F (1944) | 42.1°F (1914) | 0.42 in (1978) |
| September 10 | 102.9°F (2022) | 42.1°F (1937) | 0.08 in (1893) |
| September 11 | 104.0°F (1979) | 41.0°F (1928) | 0.05 in (1895) |
| September 12 | 108.0°F (1979) | 37.0°F (1985) | 0.76 in (1918) |
| September 13 | 109.0°F (1971) | 39.0°F (1970) | 2.00 in (1918) |
| September 14 | 109.0°F (1971) | 39.0°F (1970) | 0.52 in (1955) |
| September 15 | 109.0°F (1971) | 41.0°F (1970) | 0.17 in (1997) |
| September 16 | 109.0°F (1913) | 39.9°F (1936) | 0.63 in (1961) |
| September 17 | 105.1°F (1913) | 39.9°F (1926) | 0.90 in (1989) |
| September 18 | 106.0°F (1913) | 36.0°F (1929) | 1.85 in (1959) |
| September 19 | 107.1°F (1919) | 30.9°F (1929) | 0.54 in (2022) |
| September 20 | 102.9°F (1943) | 33.1°F (1929) | 0.11 in (1973) |
| September 21 | 104.0°F (1939) | 39.0°F (1929) | 0.51 in (2013) |
| September 22 | 102.9°F (1939) | 37.9°F (1924) | 0.35 in (1923) |
| September 23 | 102.9°F (1936) | 37.0°F (1929) | 0.59 in (1982) |
| September 24 | 104.0°F (1964) | 37.9°F (1929) | 0.36 in (1986) |
| September 25 | 100.9°F (1960) | 37.9°F (1926) | 0.58 in (1923) |
| September 26 | 102.0°F (1963) | 37.0°F (1934) | 0.75 in (1972) |
| September 27 | 102.9°F (1921) | 37.0°F (1924) | 0.56 in (1957) |
| September 28 | 102.0°F (1921) | 37.9°F (1924) | 0.50 in (1976) |
| September 29 | 100.0°F (1966) | 37.9°F (1924) | 0.62 in (1989) |
| September 30 | 102.9°F (1980) | 37.9°F (1924) | 1.61 in (1894) |