Climate almanac
Grinnell
Iowa, United States · 41.74°, -92.72°
What is the weather like in Grinnell in September?
In September, Grinnell is typically 79°F (26°C) during the day and 58°F (14°C) at night. The month brings about 3.7 in (94 mm) of precipitation in total.
- Average high79°F (26°C)
- Average low58°F (14°C)
- Precipitation3.7 in (94 mm)
- Clear or mostly clear days15
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)