15-Day Weather Forecast - Seattle

15-day weather forecast for Seattle: temperatures from 10°C (50°F) to 31°C (88°F). Average daily high 23°C (73°F) over the next 15 days.

Hourly Forecast by Day

Today·10 Sep
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Temperature · peaks at +20°C

15-Day Temperature Trend

20°14°TodaySep19°12°Tmrw19°11°Sat21°12°Sun21°13°Mon23°10°Tue25°11°Wed31°13°Thu29°15°Fri25°14°Sat24°12°Sun21°11°Mon24°11°Tue22°11°Wed24°12°Thu
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Thu, Sep 10Today
    +20°/+14°
    feels +20°0 mm · 2%12 km/hUV 3 · Mod
    06:4019:31
  • Fri, Sep 11Tomorrow
    +19°/+12°
    feels +17°0.4 mm · 3%15 km/hUV 5 · Mod
    06:4119:29
  • Sat, Sep 12Sat
    +19°/+11°
    feels +18°1.8 mm · 68%12 km/hUV 4 · Mod
    06:4219:27
  • Sun, Sep 13Sun
    +21°/+12°
    feels +18°0.1 mm · 70%20 km/hUV 4 · Mod
    06:4419:24
  • Mon, Sep 14Mon
    +21°/+13°
    feels +21°0 mm · 3%11 km/hUV 5 · Mod
    06:4519:22
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  • Tue, Sep 15Tue
    +23°/+10°
    feels +21°0 mm · 1%13 km/hUV 5 · Mod
    06:4619:20
  • Wed, Sep 16Wed
    +25°/+11°
    feels +24°12 km/hUV 5 · Mod
    06:4819:18
  • Thu, Sep 17Thu
    +31°/+13°
    feels +30°8 km/hUV 5 · Mod
    06:4919:16
  • Fri, Sep 18Fri
    +29°/+15°
    feels +28°0 mm · 2%11 km/hUV 5 · Mod
    06:5019:14
  • Sat, Sep 19Sat
    +25°/+14°
    feels +24°0 mm · 7%13 km/hUV 5 · Mod
    06:5219:12
  • Sun, Sep 20Sun
    +24°/+12°
    feels +24°0 mm · 9%15 km/hUV 5 · Mod
    06:5319:10
  • Mon, Sep 21Mon
    +21°/+11°
    feels +19°0 mm · 4%13 km/hUV 5 · Mod
    06:5419:08
  • Tue, Sep 22Tue
    +24°/+11°
    feels +22°0 mm · 6%10 km/hUV 5 · Mod
    06:5619:06
  • Wed, Sep 23Wed
    +22°/+11°
    feels +20°0 mm · 3%13 km/hUV 5 · Mod
    06:5719:04
  • Thu, Sep 24Thu
    +24°/+12°
    feels +22°0 mm · 3%14 km/hUV 5 · Mod
    06:5919:02

Weather Insight

Seattle's 15-day outlook ranges from a low of 10°C to a high of 31°C, with an average daytime high near 23°C. That's 2° above the long-term average high of 21°C for this time of year. It continues a recent pattern — 11 of the last 20 days with published data have run warmer than normal. Air quality is currently Moderate (AQI 58), driven mainly by PM2.5 at 13 μg/m³.

Today vs Normal

20°C-1° below normal

The long-term average high for today is 21°C.

11 of the last 20 days with published data ran above normal.

That's a break from the pattern - today's forecast runs below normal even though the recent stretch mostly ran above.

2026-08-19: 26°C26°2026-08-20: 27°C27°2026-08-21: 26°C26°2026-08-22: 22°C22°2026-08-23: 20°C20°2026-08-24: 25°C25°2026-08-25: 27°C27°2026-08-26: 22°C22°2026-08-27: 20°C20°2026-08-28: 19°C19°2026-08-29: 18°C18°2026-08-30: 19°C19°

Red = above normal, blue = at or below · last 12 days

Air Quality

Air Quality
Moderate

Air quality is acceptable for most people. Unusually sensitive individuals should consider reducing prolonged or heavy outdoor exertion.

Extended Outlook for Seattle

Over the next 15 days, Seattle is forecast to see temperatures ranging from 10°C to 32°C, averaging a daily high of 23°C. The extended outlook indicates occasional showers on 3 days, with 2.3 mm total accumulation. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.