Average temperatures, rainfall and packing tips for Seattle, United States in December
December in Seattle is typically cool, with average daytime highs around 9°C and nights near 5°C. It is one of the cooler months of Seattle's year.
December is one of the wetter months in Seattle, with around 202 mm of rain - plan around showers.
If your dates are flexible, the most comfortable months in Seattle are usually June, July, August and September.
← Seattle weather tomorrow (live)
In December, Seattle averages a daytime high of about 9°C and a night-time low of around 5°C, based on recent historical data.
December is one of the wetter months in Seattle, with around 202 mm of rain - plan around showers.
December is a workable time to visit Seattle, with cool days - just pack accordingly. If your dates are flexible, the most comfortable months in Seattle are usually June, July, August and September.