Collinsville

What is the climate like in Collinsville?

The best time to visit Collinsville is typically September – October, with trip comfort peaking in September (7.1/10). Collinsville 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 April and the driest is December; the year sees roughly 46 in (1180 mm) of precipitation.

• Best time to visitSeptember – October — comfort peaks in September (7.1/10)
• Warmest monthJuly — average high 88°F (31°C)
• Coolest monthJanuary — average low 26°F (-3°C)
• Wettest monthApril (5.5 in (141 mm))
• Driest monthDecember (2.5 in (64 mm))
• Annual precipitation46 in (1180 mm)
• Based on2016-2025 daily ERA5 reanalysis data (10-year normals)
• Records fromBelleville Siu Rsch, 21 km away (1948-2026)