September in Fairfield averages a daily high of 24.1°C with nights around 15.5°C. Expect roughly 8 wet days totalling 102.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Fairfield is June–September.
Based on IGOR I SIKORSKY MEMORIAL AIRPORT, CT US (11.8km), 1995–2024. 30 years of September data.