Verdict: Tough month
Seattle Weather in December
December is properly cold in Seattle, with highs of only 8°C (46°F). It's also the wet side of the calendar: rain falls on about 20 days, so build flexibility into plans. If your dates are flexible, most travelers will have a better time in Seattle outside December.
Average high
8°C / 46°F
Average low
3°C / 37°F
Rain days
~20
Precipitation
189 mm
What to pack for Seattle in December
- A proper warm jacket, and a hat for mornings
- Rain gear is non-negotiable — expect rain on roughly 20 days
- Comfortable walking shoes — every guide on this site assumes you'll use them
December against the rest of the year
Warmest in Seattle: Jul (25°C / 77°F) · Coolest: Jan (8°C / 46°F) · Wettest: Jan (~20 rain days)
8°
3°
Jan
8°
3°
Feb
10°
3°
Mar
13°
5°
Apr
17°
9°
May
21°
12°
Jun
25°
15°
Jul
25°
15°
Aug
21°
13°
Sep
15°
9°
Oct
10°
5°
Nov
8°
3°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)