September in Spokane averages a daily high of 23.2°C with nights around 9.3°C. Expect roughly 5.1 wet days totalling 15.9mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Spokane is June–September.
Based on SPOKANE INTERNATIONAL AIRPORT, WA US (8.5km), 1995–2024. 30 years of September data.