Climate almanac
New Castle
Delaware, United States · 39.66°, -75.56°
What is the weather like in New Castle in September?
In September, New Castle is typically 79°F (26°C) during the day and 63°F (17°C) at night. The month brings about 4.1 in (103 mm) of precipitation in total.
- Average high79°F (26°C)
- Average low63°F (17°C)
- Precipitation4.1 in (103 mm)
- Clear or mostly clear days12
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)