What December feels like in Seattle
December is early winter in Seattle. Daytime temperatures stay cold, and a warm coat is needed even in the middle of the day. Little changes after sunset — nights are cold, only slightly below the daytime level. The air is damp, which makes cool temperatures feel colder, particularly in wind.
Rain in Seattle in December
December is persistently wet here: some rain falls on about every other day. Rainy days are intense, averaging about 9.9 mm (0.4 in) — downpours rather than drizzle. The yearly figure is similar, around 8.3 mm per wet day. It is among the three wettest months of the year.
Daylight and sunshine in December
Mid-month, Seattle gets 8 h 28 min of daylight, from sunrise near 7:50 am to sunset near 4:18 pm. Evenings are drawing in — 53 min less daylight than mid-November. The sun is out for roughly 46% of those daylight hours, so sun and cloud share the day.
How December compares to the rest of the year
In Seattle's temperature order, December sits as the coolest month. Compared with November, afternoons are 3°C (5.4°F) cooler, with 12 mm less rain. The cooling trend carries on into January. By January, typical highs are 7.5°C (45.5°F).
Who December suits
- Sightseeing: less ideal — rain falls on more than half the days.
- Parks & outdoor: less ideal — too cool to sit outside for long.
- Beach: less ideal — the sea air is too cool.
- Hiking: less ideal — trails are cool.
- Museums & indoor: a good choice — with rain on most days, galleries and museums make easy plans.
Tips for visiting Seattle in December
Rain Protection
A packable rain jacket saves the day on showery afternoons.
Warm Layers
A warm jacket, a hat and gloves for cold mornings and evenings.
Quick questions
How warm is Seattle in December?
Afternoons average 6.9°C (44.4°F) and nights about 2.3°C (36.1°F) — cold by most people's standards. It is the coolest month of the year.
Does it rain a lot in Seattle in December?
Quite a lot — 179 mm spread over about 18 days.
What should I wear in Seattle in December?
Pack rain protection and warm layers. There is little need to change for the evening.
Is December or January better for visiting Seattle?
January, narrowly: it ranks #11 of 12 among Seattle's months, against #12 for the other.