Petaluma Weather in January

The climate in Petaluma during January can be summarized as cool and wet.

January is in the winter in Petaluma and is typically the coldest month of the year. Daytime maximum temperatures average around a cool 14°C (56°F), whilst at night 3°C (37°F) is normal.

On average January is the wettest month of the year in Petaluma with around 181mm 7.1 inches of rain making it a wet time to visit. This rainfall is typically spread over 11 days, although this may vary considerably.

On the flip side this corresponds to an average of 6.2 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Petaluma in January 2024.