Seattle, WA Weather
Seattle hourly forecast: next 24 hours
Today's high of 74°F (24°C) is about 5°F (3°C) above the typical September high of 69°F (20°C).
Current conditions in detail
Seattle weather tomorrow (Thursday, September 17)
Tomorrow in Seattle looks sunny, with a high of 77° and an overnight low of 54°. Rain is unlikely (3% chance). Winds top out near 6 mph, and the UV index reaches 5 (moderate).
Seattle 14-day forecast
About the weather in Seattle
Seattle runs on a dry-summer rhythm: the warmest months are also the driest. July averages 14 mm (0.6 in) while the wet season peaks in December at 7.4 inches (189 mm). Highs range from 45°F (7°C) to 77°F (25°C).
Seattle weather: quick facts
- Hottest month: August - highs near 77°F (25°C)
- Coldest month: December - highs near 45°F (7°C)
- Decade extremes (2015-2024): 100°F (38°C) high · 14°F (-10°C) low
- Wettest month: December (19 rainy days) · Sunniest: July (12.7 h sun/day)
- Climate type: oceanic
- Annual swing: 14°C between the average warmest and coolest month · day to night: 7°C
- Snow: about 7 days a year
- Average humidity: 77%
Temperatures through the year
Sunshine averages 8.0 hours a day over the year - duller than about 83% of the cities we track, peaking in July at 12.7 hours. December sits at the other end of the year: 45°F (7°C) by day, 37°F (3°C) at night. August is the warm end of the year, averaging 77°F (25°C) by day and 59°F (15°C) overnight. The gridded 2015-2024 daily record for this location tops out at 100°F (38°C) and bottoms at 14°F (-10°C) - decade extremes, not all-time station records. Precipitation concentrates in December - 7.4 inches (189 mm) on 19 days - and thins out by July.
Rain, sun and snow
Four of the twelve months pair mild highs with fewer than twelve wet days; the longest unbroken run is June through September.
Season by season
Spring (March through May)
Spring is crisp but comfortable here - highs near 58°F (14°C), nights near 43°F (6°C), and rain falls on around 39 of the 90 days.
Summer (June through August)
Summer in Seattle settles into easy warmth, with daytime highs averaging 74°F (23°C) and nights around 57°F (14°C); rain comes on about 17 days over the three months. Daylight is generous - around 12.0 hours of sun a day.
Fall (September through November)
Fall stays on the cool side of mild here - highs near 59°F (15°C), nights near 48°F (9°C), and rain falls on around 42 of the 90 days.
Winter (December through February)
Winter is brisk and cold here - highs near 46°F (8°C), nights near 37°F (3°C), and rain falls on around 53 of the 90 days, plus about 6 snowy days.
Average temperatures in Seattle by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 47° | 37° | 18 | 7.3 in | 4.1 h/day | 84% |
| February | 47° | 36° | 15 | 4.9 in | 5.1 h/day | 82% |
| March | 52° | 39° | 15 | 4.3 in | 7.5 h/day | 80% |
| April | 57° | 42° | 14 | 3.3 in | 9.2 h/day | 77% |
| May | 64° | 49° | 10 | 2.1 in | 10.1 h/day | 74% |
| June | 70° | 54° | 8 | 2.0 in | 11.7 h/day | 70% |
| July | 76° | 58° | 3 | 0.6 in | 12.7 h/day | 66% |
| August | 77° | 59° | 5 | 1.1 in | 11.5 h/day | 68% |
| September | 69° | 55° | 10 | 2.5 in | 9.2 h/day | 76% |
| October | 59° | 48° | 14 | 5.0 in | 6.5 h/day | 82% |
| November | 50° | 41° | 18 | 6.9 in | 4.7 h/day | 83% |
| December | 45° | 37° | 19 | 7.4 in | 3.6 h/day | 84% |