Tomorrow's Weather Forecast - San Juan

Tomorrow's weather in San Juan. high 30°C (86°F), low 27°C (81°F). Drizzle.

Tomorrow’s Outlook

Tomorrow brings a similar temperature to today. Showers are likely in the afternoon and evening, with rain probability peaking near 69%. That risk lines up with humidity averaging 76% through the day the more moisture in the air, the more readily clouds build into showers. Humidity stays high near 76%, so it will feel muggier and stickier than the temperature alone suggests. Expect a steady breeze around 25 km/h through the day. Sunrise is at 6:11 AM and sunset at 6:29 PM, for about 12h 18m of daylight.

Tomorrow
30°/ 27°
Today30° / 27°

Tomorrow’s Hourly Weather Outlook

Morning6 AM – Noon29°
Rain probability
24%
Wind speed
22 km/h
AfternoonNoon – 6 PM30°
Rain probability
69%
Wind speed
25 km/h
Evening6 PM – Midn29°
Rain probability
50%
Wind speed
22 km/h
NightMidn – 6 AM28°
Rain probability
0%
Wind speed
17 km/h

24-Hour Rain & Temperature Forecast

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Temperature · peaks at +30°C

Planning Advice for Tomorrow

Clothing
Light waterproof jacket with an umbrella is a smart choice.
Outdoor
Outdoor plans may need flexibility; showers are likely.
Travel
Wet roads may slow traffic; allow a little extra time.

Sunrise & Sunset

Sunrise
Dawn 5:41 AM
Total Daylight
Full day forecastSolar noon 12:20 PM
Sunset
Dusk 6:59 PM
vs today-1 min daylight
Sunrise shiftSame time
Sunset shift1 min earlier

5-Day Weather Forecast

Full 15-Day Forecast

Weather Insight

San Juan is forecast to reach a high of 30°C tomorrow, with an overnight low around 27°C. Expect a high chance of rain (69% probability) and moderate breezes averaging 25 km/h. Air quality is currently Moderate (AQI 65), driven mainly by PM2.5 at 18 μg/m³.

Today vs Normal

30°C0° below normal

The long-term average high for today is 30°C.

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

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

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

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.