15-Day Weather Forecast - Londonderry

15-day weather forecast for Londonderry: temperatures from 9°C (48°F) to 18°C (64°F). Average daily high 15°C (59°F) over the next 15 days.

Hourly Forecast by Day

Today·11 Sep
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Temperature · peaks at +17°C

15-Day Temperature Trend

17°13°TodaySep17°13°Tmrw18°11°Sun18°13°Mon15°11°Tue15°12°Wed14°11°Thu14°11°Fri14°10°Sat14°10°Sun16°13°Mon14°11°Tue12°9°Wed11°9°Thu14°9°Fri
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Fri, Sep 11Today
    +17°/+13°
    feels +15°1.1 mm · 28%17 km/hUV 2 · Low
    06:5419:56
  • Sat, Sep 12Tomorrow
    +17°/+13°
    feels +16°20.3 mm · 100%29 km/hUV 2 · Low
    06:5519:53
  • Sun, Sep 13Sun
    +18°/+11°
    feels +18°0.2 mm · 10%16 km/hUV 2 · Low
    06:5719:51
  • Mon, Sep 14Mon
    +18°/+13°
    feels +18°11.8 mm · 82%21 km/hUV 3 · Mod
    06:5919:48
  • Tue, Sep 15Tue
    +15°/+11°
    feels +12°3.0 mm · 87%27 km/hUV 4 · Mod
    07:0119:46
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  • Wed, Sep 16Wed
    +15°/+12°
    feels +12°1.6 mm · 59%32 km/hUV 1 · Low
    07:0319:43
  • Thu, Sep 17Thu
    +14°/+11°
    feels +11°3.4 mm · 73%31 km/hUV 3 · Mod
    07:0519:40
  • Fri, Sep 18Fri
    +14°/+11°
    feels +10°1.7 mm · 51%31 km/hUV 2 · Low
    07:0719:38
  • Sat, Sep 19Sat
    +14°/+10°
    feels +10°2.4 mm · 57%27 km/hUV 3 · Mod
    07:0819:35
  • Sun, Sep 20Sun
    +14°/+10°
    feels +11°0.2 mm · 57%22 km/hUV 3 · Low
    07:1019:33
  • Mon, Sep 21Mon
    +16°/+13°
    feels +15°10.2 mm · 44%24 km/hUV 4 · Mod
    07:1219:30
  • Tue, Sep 22Tue
    +14°/+11°
    feels +13°3.6 mm · 39%29 km/hUV 2 · Low
    07:1419:28
  • Wed, Sep 23Wed
    +12°/+9°
    feels +6°1.2 mm · 53%28 km/hUV 3 · Low
    07:1619:25
  • Thu, Sep 24Thu
    +11°/+9°
    feels +7°0 mm · 42%21 km/hUV 2 · Low
    07:1819:23
  • Fri, Sep 25Fri
    +14°/+9°
    feels +13°0.6 mm · 35%16 km/hUV 2 · Low
    07:2019:20

Weather Insight

Londonderry's 15-day outlook ranges from a low of 9°C to a high of 18°C, with an average daytime high near 15°C. Air quality is currently Moderate (AQI 52), driven mainly by PM2.5 at 9.5 μg/m³.

Today vs Normal

17°C+2° above normal

The long-term average high for today is 15°C.

9 of the last 19 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.

2026-08-19: 16°C16°2026-08-20: 14°C14°2026-08-21: 15°C15°2026-08-22: 15°C15°2026-08-23: 16°C16°2026-08-24: 19°C19°2026-08-25: 17°C17°2026-08-26: 18°C18°2026-08-27: 20°C20°2026-08-28: 19°C19°2026-08-29: 16°C16°2026-08-30: 18°C18°

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 Londonderry

Over the next 15 days, Londonderry is forecast to see temperatures ranging from 8°C to 19°C, averaging a daily high of 15°C. The extended outlook indicates significant rainfall totalling 61.3 mm spread across 14 days. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.