March in Fountain Valley averages a daily high of 20.1°C with nights around 11.2°C. Expect roughly 5.7 wet days totalling 33.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Fountain Valley is April–November.
Based on SANTA ANA JOHN WAYNE AIRPORT, CA US (8.6km), 1995–2024. 25 years of March data.