January in Florissant averages a daily high of 4.9°C with nights around -4.2°C. Expect roughly 9.3 wet days totalling 68.5mm. A hard month to visit for comfort alone.
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 January data.