October in Tri-Cities averages a daily high of 19°C with nights around 3.9°C. Expect roughly 6.1 wet days totalling 16.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Tri-Cities is April–May.
Based on PASCO TRI CITIES AIRPORT, WA US (6.6km), 1995–2024. 27 years of October data.