California, United States of America · population 60,438 · 362 weather stations within 200 km · records 1837 to 2025
Petaluma has an average annual daytime high of 18.5°C, based on the 1951 to 1980 baseline. Its warmest month is September, when highs typically reach 23.6°C, and its coldest is January, with overnight lows near 4.1°C.
These figures reflect annual averages, not single-day records. Daily observations are outside this dataset's precision.
Since 1900, Petaluma's average temperature has risen by +1.3°C. Compared to the earliest station records that begin in 1837, warming totals +1.7°C.
20-year smoothed annual temperature reconstructed from station anomalies. Dashed line: 1951–1980 baseline.
Daytime highs sit within a comfortable 15°C to 26°C range.
Petaluma's average annual daytime high is 18.5°C, based on the 1951 to 1980 baseline period. The warmest month is September, with highs averaging 23.6°C, and the coldest is January, with lows averaging 4.1°C.
September is the warmest month in Petaluma, with typical daytime highs of 23.6°C.
2014 is the hottest year on record for Petaluma, running +1.9°C above the 1951 to 1980 baseline.
Yes. Since 1900, Petaluma has warmed by roughly +1.3°C.
March to November typically offers the most comfortable daytime highs, in the 15°C to 26°C range.
Baseline period 1951 to 1980. Monthly averages are the mean of station observations weighted by proximity. Warming trend is the 20-year smoothed anomaly against that baseline.