Seattle in December
4.0out of 10
Not the best time
Cold: highs around 8°C. Very wet: about 18 rainy days.
8°CAvg high
4°CAvg low
18Rainy days (178 mm)
8:15 hDaylight
07:58Sunrise · 16:13 Sunset
Why this score
- Cold: highs around 8°C
- Very wet: about 18 rainy days
- Rain varies a lot between years (±4.2 days)
What to wear and pack
- A warm jacket
- Rain jacket or compact umbrella
How reliable is the forecast?
Rain in December varies a lot between years (±4.2 rainy days), so check the forecast closer to your trip. Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | 8°C | 4°C | 176 mm | 18 | – | – | 4.0 |
| February | 10°C | 4°C | 122 mm | 14 | – | – | 5.0 |
| March | 12°C | 5°C | 139 mm | 17 | – | – | 4.9 |
| April | 15°C | 7°C | 114 mm | 16 | – | – | 5.6 |
| May | 18°C | 10°C | 76 mm | 13 | – | – | 6.8 |
| June | 21°C | 12°C | 60 mm | 10 | – | – | 7.6 |
| July | 25°C | 14°C | 25 mm | 5 | – | – | 8.4 |
| August | 25°C | 14°C | 32 mm | 5 | – | – | 8.4 |
| September | 22°C | 12°C | 67 mm | 8 | – | – | 7.9 |
| October | 16°C | 9°C | 134 mm | 15 | – | – | 5.9 |
| November | 11°C | 6°C | 192 mm | 18 | – | – | 4.3 |
| December | 8°C | 4°C | 178 mm | 18 | – | – | 4.0 |
Frequently asked questions
How hot is Seattle in December?
Daytime highs average 8°C and nights about 4°C.
When is the best time to visit Seattle?
The best months are July, August, September.