15-Day Weather Forecast - Boulder

15-day weather forecast for Boulder: temperatures from 9°C (48°F) to 33°C (91°F). Average daily high 28°C (82°F) over the next 15 days.

Hourly Forecast by Day

Today·11 Sep
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Temperature · peaks at +31°C

15-Day Temperature Trend

31°16°TodaySep30°13°Tmrw33°17°Sun29°18°Mon23°12°Tue28°15°Wed23°11°Thu23°9°Fri26°10°Sat31°15°Sun33°18°Mon31°16°Tue21°14°Wed27°11°Thu31°15°Fri
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Fri, Sep 11Today
    +31°/+16°
    feels +30°0 mm · 2%21 km/hUV 7 · Hi
    06:3819:16
  • Sat, Sep 12Tomorrow
    +30°/+13°
    feels +28°0 mm · 3%13 km/hUV 7 · Hi
    06:3919:14
  • Sun, Sep 13Sun
    +33°/+17°
    feels +31°0.5 mm · 17%41 km/hUV 7 · Hi
    06:4019:12
  • Mon, Sep 14Mon
    +29°/+18°
    feels +28°0.8 mm · 39%26 km/hUV 4 · Mod
    06:4119:11
  • Tue, Sep 15Tue
    +23°/+12°
    feels +21°2.3 mm · 59%15 km/hUV 6 · Mod
    06:4219:09
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  • Wed, Sep 16Wed
    +28°/+15°
    feels +27°1.6 mm · 43%18 km/hUV 4 · Mod
    06:4319:07
  • Thu, Sep 17Thu
    +23°/+11°
    feels +20°0.1 mm · 40%19 km/hUV 7 · Hi
    06:4419:06
  • Fri, Sep 18Fri
    +23°/+9°
    feels +22°0 mm · 23%16 km/hUV 7 · Hi
    06:4419:04
  • Sat, Sep 19Sat
    +26°/+10°
    feels +23°0 mm · 27%17 km/hUV 7 · Hi
    06:4519:02
  • Sun, Sep 20Sun
    +31°/+15°
    feels +26°0 mm · 28%20 km/hUV 7 · Hi
    06:4619:01
  • Mon, Sep 21Mon
    +33°/+18°
    feels +28°0 mm · 23%29 km/hUV 6 · Hi
    06:4718:59
  • Tue, Sep 22Tue
    +31°/+16°
    feels +27°3.3 mm · 27%19 km/hUV 5 · Mod
    06:4818:57
  • Wed, Sep 23Wed
    +21°/+14°
    feels +20°1.8 mm · 29%13 km/hUV 3 · Mod
    06:4918:56
  • Thu, Sep 24Thu
    +27°/+11°
    feels +24°0 mm · 29%15 km/hUV 7 · Hi
    06:5018:54
  • Fri, Sep 25Fri
    +31°/+15°
    feels +28°0 mm · 23%18 km/hUV 7 · Hi
    06:5118:52

Weather Insight

Boulder's 15-day outlook ranges from a low of 9°C to a high of 33°C, with an average daytime high near 28°C. That's 1° above the long-term average high of 27°C for this time of year. It continues a recent pattern — 24 of the last 28 days with published data have run warmer than normal. Air quality is currently good (AQI 22), with no notable outdoor health concerns.

Today vs Normal

31°C+4° above normal

The long-term average high for today is 27°C.

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

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

2026-08-28: 34°C34°2026-08-29: 29°C29°2026-08-30: 30°C30°2026-08-31: 29°C29°2026-09-01: 30°C30°2026-09-02: 30°C30°2026-09-03: 32°C32°2026-09-04: 32°C32°2026-09-05: 33°C33°2026-09-06: 32°C32°2026-09-07: 31°C31°2026-09-08: 29°C29°

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 Boulder

Over the next 15 days, Boulder is forecast to see temperatures ranging from 9°C to 34°C, averaging a daily high of 28°C. The extended outlook indicates occasional showers on 7 days, with 10.4 mm total accumulation. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.