15-Day Weather Forecast - Portland

15-day weather forecast for Portland: temperatures from 11°C (52°F) to 32°C (90°F). Average daily high 24°C (75°F) over the next 15 days.

Hourly Forecast by Day

Today·11 Sep
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Temperature · peaks at +20°C

15-Day Temperature Trend

20°11°TodaySep17°12°Tmrw19°12°Sun22°12°Mon24°11°Tue30°11°Wed32°14°Thu30°16°Fri26°16°Sat22°14°Sun20°14°Mon24°14°Tue25°12°Wed29°15°Thu26°15°Fri
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Fri, Sep 11Today
    +20°/+11°
    feels +20°0 mm · 1%9 km/hUV 6 · Mod
    06:4419:29
  • Sat, Sep 12Tomorrow
    +17°/+12°
    feels +17°3.1 mm · 85%9 km/hUV 5 · Mod
    06:4519:27
  • Sun, Sep 13Sun
    +19°/+12°
    feels +18°3.5 mm · 74%15 km/hUV 3 · Low
    06:4719:25
  • Mon, Sep 14Mon
    +22°/+12°
    feels +21°8 km/hUV 6 · Mod
    06:4819:23
  • Tue, Sep 15Tue
    +24°/+11°
    feels +23°0 mm · 1%13 km/hUV 5 · Mod
    06:4919:21
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  • Wed, Sep 16Wed
    +30°/+11°
    feels +27°12 km/hUV 6 · Mod
    06:5019:19
  • Thu, Sep 17Thu
    +32°/+14°
    feels +29°0 mm · 1%16 km/hUV 5 · Mod
    06:5119:17
  • Fri, Sep 18Fri
    +30°/+16°
    feels +29°0 mm · 1%7 km/hUV 5 · Mod
    06:5319:15
  • Sat, Sep 19Sat
    +26°/+16°
    feels +25°0 mm · 4%6 km/hUV 5 · Mod
    06:5419:13
  • Sun, Sep 20Sun
    +22°/+14°
    feels +21°0.9 mm · 5%11 km/hUV 4 · Mod
    06:5519:11
  • Mon, Sep 21Mon
    +20°/+14°
    feels +21°1.8 mm · 9%12 km/hUV 3 · Low
    06:5619:09
  • Tue, Sep 22Tue
    +24°/+14°
    feels +22°0 mm · 6%12 km/hUV 5 · Mod
    06:5819:08
  • Wed, Sep 23Wed
    +25°/+12°
    feels +24°0 mm · 10%5 km/hUV 5 · Mod
    06:5919:06
  • Thu, Sep 24Thu
    +29°/+15°
    feels +27°0 mm · 9%9 km/hUV 5 · Mod
    07:0019:04
  • Fri, Sep 25Fri
    +26°/+15°
    feels +24°0 mm · 7%11 km/hUV 5 · Mod
    07:0119:02

Weather Insight

Portland's 15-day outlook ranges from a low of 11°C to a high of 32°C, with an average daytime high near 24°C. That's 1° below the long-term average high of 25°C for this time of year. It continues a recent pattern — 3 of the last 19 days with published data have run cooler than normal. Air quality is currently Moderate (AQI 53), driven mainly by PM2.5 at 9.2 μg/m³.

Today vs Normal

20°C-5° below normal

The long-term average high for today is 25°C.

3 of the last 19 days with published data ran above normal.

It continues that pattern - today's forecast is also running below normal.

2026-08-19: 27°C27°2026-08-20: 31°C31°2026-08-21: 25°C25°2026-08-22: 22°C22°2026-08-23: 24°C24°2026-08-24: 31°C31°2026-08-25: 29°C29°2026-08-26: 25°C25°2026-08-27: 23°C23°2026-08-28: 23°C23°2026-08-29: 19°C19°2026-08-30: 21°C21°

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 Portland

Over the next 15 days, Portland is forecast to see temperatures ranging from 11°C to 32°C, averaging a daily high of 24°C. The extended outlook indicates occasional showers on 4 days, with 9.3 mm total accumulation. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.