Seattle, Washington Weather in December
Typical December in Seattle, Washington: days around 47°F, nights around 37°F, and the month cools about 2°F from early to late — based on 30-year climate normals (NOAA, 1991–2020), day by day below.
47°Faverage high
37°Faverage low
−2°Fearly vs late December
10°Fday-to-night swing
Early, mid and late December in Seattle
The month split in three — the part of the answer a 30-row table hides.
| Part of December | Avg high | Avg low |
|---|---|---|
| Early December (Dec 1–10) | 48°F | 38°F |
| Mid December (Dec 11–20) | 47°F | 37°F |
| Late December (Dec 21–31) | 46°F | 37°F |
Daylight in Seattle during December
Seattle loses 18 minutes of daylight by Dec 21 and gets 5 minutes back by Dec 31.
8 h 43 minon Dec 1
8 h 25 minshortest day · Dec 21
8 h 30 minon Dec 31
Day-by-day December normals for Seattle
Long-term daily averages (NOAA 1991–2020) — climate, not a live forecast. For the next 16 days, use the live forecast.
| Day | Avg high | Avg low |
|---|---|---|
| Dec 1 | 49°F | 38°F |
| Dec 2 | 49°F | 38°F |
| Dec 3 | 48°F | 38°F |
| Dec 4 | 48°F | 38°F |
| Dec 5 | 48°F | 38°F |
| Dec 6 | 48°F | 38°F |
| Dec 7 | 48°F | 37°F |
| Dec 8 | 48°F | 37°F |
| Dec 9 | 47°F | 37°F |
| Dec 10 | 47°F | 37°F |
| Dec 11 | 47°F | 37°F |
| Dec 12 | 47°F | 37°F |
| Dec 13 | 47°F | 37°F |
| Dec 14 | 47°F | 37°F |
| Dec 15 | 47°F | 37°F |
| Dec 16 | 47°F | 37°F |
| Dec 17 | 46°F | 37°F |
| Dec 18 | 46°F | 37°F |
| Dec 19 | 46°F | 37°F |
| Dec 20 | 46°F | 37°F |
| Dec 21 | 46°F | 37°F |
| Dec 22 | 46°F | 37°F |
| Dec 23 | 46°F | 37°F |
| Dec 24 | 46°F | 37°F |
| Dec 25 | 46°F | 37°F |
| Dec 26 | 46°F | 37°F |
| Dec 27 | 46°F | 37°F |
| Dec 28 | 46°F | 37°F |
| Dec 29 | 46°F | 37°F |
| Dec 30 | 47°F | 37°F |
| Dec 31 | 47°F | 37°F |
December in Seattle through the years
Real photos taken in Seattle in December by Weathershot app users — different years, same month.
More months: September · October · November · January · Live Seattle forecast
December elsewhere: Atlanta weather in December · Chicago weather in December · Denver weather in December · Miami weather in December · New York weather in December · Phoenix weather in December
Weathershot
The December photos above were taken with Weathershot — it stamps the real weather onto your picture. Snap one in Seattle and it could land on this page.
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Climate normals: NOAA 1991–2020 (GHCND). Photos: Weathershot community, taken on location. © Weathershot · Byss Mobile