Climate almanac
Freeport
Illinois, United States · 42.30°, -89.62°
What is the climate like in Freeport?
The best time to visit Freeport is typically June – September, with trip comfort peaking in August (6.8/10). Freeport is warmest in July, when daily highs average 84°F (29°C), and coolest in January, when lows fall to about 17°F (-8°C). The wettest month is typically May and the driest is February; the year sees roughly 39 in (1002 mm) of precipitation.
- Best time to visitJune – September — comfort peaks in August (6.8/10)
- Warmest monthJuly — average high 84°F (29°C)
- Coolest monthJanuary — average low 17°F (-8°C)
- Wettest monthMay (4.8 in (122 mm))
- Driest monthFebruary (1.8 in (46 mm))
- Annual precipitation39 in (1002 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)
- Records fromFreeport Wwtp, 1 km away (1973-2026)