July in Florissant averages a daily high of 32°C with nights around 22°C. Expect roughly 9 wet days totalling 112.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Florissant is September–October.
Based on ST LOUIS LAMBERT INTERNATIONAL AIRPORT, MO US (6km), 1995–2024. 30 years of July data.