January in Seattle averages a daily high of 9°C with nights around 2.8°C. Expect roughly 18.5 wet days totalling 124.9mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Seattle is July–August.
Based on SEATTLE BOEING FIELD, WA US (6.9km), 1995–2024. 26 years of January data.