15-Day Weather Forecast - Trondheim

15-day weather forecast for Trondheim: temperatures from 4°C (39°F) to 17°C (63°F). Average daily high 12°C (54°F) over the next 15 days.

Hourly Forecast by Day

Today·11 Sep
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Temperature · peaks at +16°C

15-Day Temperature Trend

16°6°TodaySep16°8°Tmrw13°9°Sun13°9°Mon17°8°Tue12°10°Wed15°8°Thu13°7°Fri11°7°Sat12°9°Sun11°8°Mon10°8°Tue10°6°Wed9°5°Thu9°4°Fri
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Fri, Sep 11Today
    +16°/+6°
    feels +15°0.8 mm · 34%10 km/hUV 3 · Low
    06:3019:57
  • Sat, Sep 12Tomorrow
    +16°/+8°
    feels +16°0.5 mm · 33%14 km/hUV 2 · Low
    06:3319:53
  • Sun, Sep 13Sun
    +13°/+9°
    feels +11°1.5 mm · 27%19 km/hUV 1 · Low
    06:3619:50
  • Mon, Sep 14Mon
    +13°/+9°
    feels +11°0 mm · 7%9 km/hUV 2 · Low
    06:3919:46
  • Tue, Sep 15Tue
    +17°/+8°
    feels +15°3.3 mm · 88%24 km/hUV 1 · Low
    06:4119:43
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  • Wed, Sep 16Wed
    +12°/+10°
    feels +10°3.6 mm · 72%20 km/hUV 2 · Low
    06:4419:40
  • Thu, Sep 17Thu
    +15°/+8°
    feels +11°0.6 mm · 41%16 km/hUV 2 · Low
    06:4719:36
  • Fri, Sep 18Fri
    +13°/+7°
    feels +11°0 mm · 55%13 km/hUV 2 · Low
    06:5019:33
  • Sat, Sep 19Sat
    +11°/+7°
    feels +10°0 mm · 50%8 km/hUV 1 · Low
    06:5219:29
  • Sun, Sep 20Sun
    +12°/+9°
    feels +9°2.4 mm · 33%18 km/hUV 3 · Low
    06:5519:26
  • Mon, Sep 21Mon
    +11°/+8°
    feels +9°0.6 mm · 57%19 km/hUV 2 · Low
    06:5819:22
  • Tue, Sep 22Tue
    +10°/+8°
    feels +8°3.6 mm · 55%14 km/hUV 2 · Low
    07:0119:19
  • Wed, Sep 23Wed
    +10°/+6°
    feels +8°1.5 mm · 55%12 km/hUV 2 · Low
    07:0419:16
  • Thu, Sep 24Thu
    +9°/+5°
    feels +5°4.2 mm · 48%25 km/hUV 2 · Low
    07:0619:12
  • Fri, Sep 25Fri
    +9°/+4°
    feels +6°0.3 mm · 49%12 km/hUV 2 · Low
    07:0919:09

Weather Insight

Trondheim's 15-day outlook ranges from a low of 4°C to a high of 17°C, with an average daytime high near 12°C. That's 1° below the long-term average high of 13°C for this time of year. It continues a recent pattern — 10 of the last 28 days with published data have run cooler than normal. Air quality is currently good (AQI 22), with no notable outdoor health concerns.

Today vs Normal

16°C+3° above normal

The long-term average high for today is 13°C.

10 of the last 28 days with published data ran above normal.

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

2026-08-28: 19°C19°2026-08-29: 16°C16°2026-08-30: 12°C12°2026-08-31: 12°C12°2026-09-01: 16°C16°2026-09-02: 13°C13°2026-09-03: 10°C10°2026-09-04: 16°C16°2026-09-05: 15°C15°2026-09-06: 11°C11°2026-09-07: 15°C15°2026-09-08: 12°C12°

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

Air Quality

Air Quality
Good

Air quality is considered satisfactory, and air pollution poses little or no risk. It’s a good day to be active outside.

Extended Outlook for Trondheim

Over the next 15 days, Trondheim is forecast to see temperatures ranging from 3°C to 17°C, averaging a daily high of 12°C. The extended outlook indicates frequent showers on 12 out of 15 days. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.