Climate almanac
Decatur
Illinois, United States · 39.84°, -88.95°
What is the weather like in Decatur in May?
In May, Decatur is typically 75°F (24°C) during the day and 57°F (14°C) at night. The month brings about 4.7 in (118 mm) of precipitation in total.
- Average high75°F (24°C)
- Average low57°F (14°C)
- Precipitation4.7 in (118 mm)
- Clear or mostly clear days8
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)