Climate almanac
Tri-Cities
Washington, United States · 46.25°, -119.20°
What is the weather like in Tri-Cities in September?
In September, Tri-Cities is typically 84°F (29°C) during the day and 55°F (13°C) at night. The month brings about 0.3 in (7 mm) of precipitation in total.
- Average high84°F (29°C)
- Average low55°F (13°C)
- Precipitation0.3 in (7 mm)
- Clear or mostly clear days17
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)