15-Day Weather Forecast - Porto Alegre

15-day weather forecast for Porto Alegre: temperatures from 7°C (45°F) to 27°C (81°F). Average daily high 20°C (68°F) over the next 15 days.

Hourly Forecast by Day

Today·11 Sep
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Temperature · peaks at +19°C

15-Day Temperature Trend

19°15°TodaySep18°13°Tmrw17°12°Sun17°12°Mon18°11°Tue14°8°Wed21°7°Thu24°11°Fri25°12°Sat18°16°Sun27°16°Mon19°13°Tue16°12°Wed19°12°Thu24°12°Fri
Colour scale for daily high temperature bars

15-Day Weather Forecast

Updated just now
  • Date
    High / Low
  • Fri, Sep 11Today
    +19°/+15°
    feels +21°42.7 mm · 100%19 km/hUV 1 · Low
    06:2718:15
  • Sat, Sep 12Tomorrow
    +18°/+13°
    feels +16°1.1 mm · 35%15 km/hUV 6 · Mod
    06:2618:15
  • Sun, Sep 13Sun
    +17°/+12°
    feels +16°0.3 mm · 59%15 km/hUV 4 · Mod
    06:2518:16
  • Mon, Sep 14Mon
    +17°/+12°
    feels +17°0.7 mm · 59%8 km/hUV 1 · Low
    06:2418:16
  • Tue, Sep 15Tue
    +18°/+11°
    feels +15°1.2 mm · 51%18 km/hUV 5 · Mod
    06:2218:17
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  • Wed, Sep 16Wed
    +14°/+8°
    feels +13°0 mm · 4%12 km/hUV 3 · Low
    06:2118:17
  • Thu, Sep 17Thu
    +21°/+7°
    feels +21°9 km/hUV 7 · Hi
    06:2018:18
  • Fri, Sep 18Fri
    +24°/+11°
    feels +25°0 mm · 1%12 km/hUV 7 · Hi
    06:1918:18
  • Sat, Sep 19Sat
    +25°/+12°
    feels +26°0 mm · 15%17 km/hUV 7 · Hi
    06:1718:19
  • Sun, Sep 20Sun
    +18°/+16°
    feels +18°20.4 mm · 32%19 km/hUV 6 · Hi
    06:1618:20
  • Mon, Sep 21Mon
    +27°/+16°
    feels +29°0 mm · 29%14 km/hUV 7 · Hi
    06:1518:20
  • Tue, Sep 22Tue
    +19°/+13°
    feels +22°0 mm · 25%18 km/hUV 7 · Hi
    06:1418:21
  • Wed, Sep 23Wed
    +16°/+12°
    feels +14°0 mm · 22%12 km/hUV 7 · Hi
    06:1318:21
  • Thu, Sep 24Thu
    +19°/+12°
    feels +18°0.6 mm · 14%13 km/hUV 7 · Hi
    06:1118:22
  • Fri, Sep 25Fri
    +24°/+12°
    feels +25°6.8 mm · 24%12 km/hUV 6 · Mod
    06:1018:22

Weather Insight

Porto Alegre's 15-day outlook ranges from a low of 7°C to a high of 27°C, with an average daytime high near 20°C. That's 2° below the long-term average high of 22°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

19°C-3° below normal

The long-term average high for today is 22°C.

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

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

2026-08-28: 23°C23°2026-08-29: 17°C17°2026-08-30: 22°C22°2026-08-31: 20°C20°2026-09-01: 19°C19°2026-09-02: 21°C21°2026-09-03: 25°C25°2026-09-04: 20°C20°2026-09-05: 18°C18°2026-09-06: 14°C14°2026-09-07: 16°C16°2026-09-08: 20°C20°

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 Porto Alegre

Over the next 15 days, Porto Alegre is forecast to see temperatures ranging from 6°C to 28°C, averaging a daily high of 20°C. The extended outlook indicates significant rainfall totalling 73.8 mm spread across 8 days. Conditions are suitable for most outdoor activities; carry an umbrella on days with showers.