April in Petaluma averages a daily high of 19.9°C with nights around 6.7°C. Expect roughly 6.2 wet days totalling 41.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Petaluma is May–October.
Based on PETALUMA AIRPORT, CA US (3.8km), 1995–2024. 25 years of April data.