March in Petaluma averages a daily high of 18.2°C with nights around 5.5°C. Expect roughly 10.6 wet days totalling 88.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Petaluma is May–October.
Based on PETALUMA AIRPORT, CA US (3.8km), 1995–2024. 29 years of March data.