Climate almanac
Saint Charles
Missouri, United States · 38.78°, -90.48°
What is the climate like in Saint Charles?
The best time to visit Saint Charles is typically September – October, with trip comfort peaking in September (7.3/10). Saint Charles is warmest in July, when daily highs average 88°F (31°C), and coolest in January, when lows fall to about 26°F (-3°C). The wettest month is typically May and the driest is December; the year sees roughly 44 in (1117 mm) of precipitation.
- Best time to visitSeptember – October — comfort peaks in September (7.3/10)
- Warmest monthJuly — average high 88°F (31°C)
- Coolest monthJanuary — average low 26°F (-3°C)
- Wettest monthMay (5.1 in (130 mm))
- Driest monthDecember (2.3 in (57 mm))
- Annual precipitation44 in (1117 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)
- Records fromSt Charles Elm Pt, 4 km away (1893-2026)