Weather in San Juan - 14-day forecast

Detailed weather forecast for San Juan, Puerto Rico: daytime and night temperature, rain, sunrise and sunset - today and for the next two weeks.

Forecast for the next days in San Juan

today🌧️ 32°💧 0.1 mm

Sun🌧️ 34°💧 0.2 mm

Mon🌧️ 33°💧 0.8 mm

Tue🌧️ 31°💧 0.3 mm

Wed🌧️ 31°💧 1 mm

Thu🌧️ 31°💧 0.6 mm

Fri🌧️ 30°💧 0.4 mm

Sat🌤️ 32°💧 0.5 mm

Forecast vs 1991-2020 climate normal

How does the current forecast compare with normal?

We compare the coming days with weather usually observed at this time of year.

NASA POWER

Sunday 6 Sept in San Juan, the forecast high is 34°C. Typical daytime temperatures at this time of year range from 29°C to 31°C, so it will be exceptionally warm. It is warmer than 99% of similar days.

Saturday 5 Sept

32°Cexceptionally warm

usually 29°C–31°C

warmer than 93% of similar days

night: exceptionally warm rain: exceptionally dry wind: exceptionally strong

Sunday 6 Sept

34°Cexceptionally warm

usually 29°C–31°C

warmer than 99% of similar days

night: exceptionally warm rain: exceptionally dry wind: stronger than usual

Monday 7 Sept

33°Cexceptionally warm

usually 29°C–31°C

warmer than 99% of similar days

night: exceptionally warm rain: exceptionally dry wind: stronger than usual

Tuesday 8 Sept

31°Cwarmer than usual

usually 29°C–31°C

warmer than 88% of similar days

night: near normal rain: exceptionally dry wind: exceptionally strong

Wednesday 9 Sept

31°Cwarmer than usual

usually 29°C–31°C

warmer than 73% of similar days

night: exceptionally warm rain: exceptionally dry wind: exceptionally strong

Thursday 10 Sept

31°Cwarmer than usual

usually 29°C–31°C

warmer than 87% of similar days

night: exceptionally warm rain: exceptionally dry wind: exceptionally strong

Friday 11 Sept

30°Cnear normal

usually 29°C–31°C

night: exceptionally warm rain: exceptionally dry wind: exceptionally strong

How warm was this week in previous years?

Each bar shows the average daily high during the same 7-day period in each year.

swipe to see more years →

cooler yearstypical rangewarmer years2026 forecastcurrent forecast

From 1981 to 2025, the 5-11 Sept period averaged 30°C by day. The coolest year was 1996 (28°C) and the warmest was 2015 (32°C). The current forecast averages 32°C - higher than in 100% of historical years.

Historical reference: NASA POWER daily gridded data (MERRA-2), the 1991-2020 normal and a +/- 7-day calendar window. The typical range is the 20th-80th percentile. This is not a city weather-station reading and does not change the current forecast. NASA POWER Daily API.

14-day forecast - San Juan

San Juan - 14-day weather forecast infographic

San Juan 30 & 45-day weather - long-range outlook

Next 15 days · forecast

31°

around 27° at night · days with rain: 3

Weeks 3-4 · avg for September

32°

around 26° at night · rain chance 50%

Weeks 5-7 · avg for October

32°

around 26° at night · rain chance 49%

The 30 & 45-day outlook for San Juan: the next 15 days are a numerical forecast updated daily - on average 31° by day and 27° at night. Further out we rely on multi-year climate averages: around 32° in September, and about 32° in October. Forecasts beyond two weeks are indicative only.

Day-by-day forecast for San Juan

Saturday5 September 2026

🌧️32°light rain

sunrise 06:10 · sunset 18:36 · night 29° · evening 31° · rain 0.13 mm · humidity 64% · wind 8 m/s · clouds 96%

Sunday6 September 2026

🌧️34°light rain

sunrise 06:11 · sunset 18:35 · night 27° · evening 31° · rain 0.22 mm · humidity 59% · wind 7 m/s · clouds 81%

Monday7 September 2026

🌧️33°light rain

sunrise 06:11 · sunset 18:34 · night 28° · evening 30° · rain 0.81 mm · humidity 60% · wind 7 m/s · clouds 79%

Tuesday8 September 2026

🌧️31°light rain

sunrise 06:11 · sunset 18:33 · night 27° · evening 30° · rain 0.34 mm · humidity 62% · wind 7 m/s · clouds 35%

Wednesday9 September 2026

🌧️31°light rain

sunrise 06:11 · sunset 18:32 · night 27° · evening 30° · rain 1 mm · humidity 65% · wind 8 m/s · clouds 42%

Thursday10 September 2026

🌧️31°light rain

sunrise 06:11 · sunset 18:31 · night 27° · evening 31° · rain 0.57 mm · humidity 63% · wind 7 m/s · clouds 95%

Friday11 September 2026

🌧️30°light rain

sunrise 06:11 · sunset 18:30 · night 28° · evening 31° · rain 0.39 mm · humidity 67% · wind 8 m/s · clouds 100%

Saturday12 September 2026

🌤️32°a few clouds

sunrise 06:12 · sunset 18:30 · night 27° · evening 31° · rain 0.48 mm · humidity 59% · wind 8 m/s · clouds 22%

Sunday13 September 2026

🌧️31°light rain

sunrise 06:12 · sunset 18:29 · night 27° · evening 30° · rain 1.95 mm · humidity 56% · wind 8 m/s · clouds 95%

Monday14 September 2026

🌧️31°light rain

sunrise 06:12 · sunset 18:28 · night 27° · evening 30° · rain 1.26 mm · humidity 61% · wind 8 m/s · clouds 29%

Tuesday15 September 2026

🌧️31°light rain

sunrise 06:12 · sunset 18:27 · night 26° · evening 30° · rain 0.54 mm · humidity 58% · wind 8 m/s · clouds 29%

Wednesday16 September 2026

🌧️31°light rain

sunrise 06:12 · sunset 18:26 · night 27° · evening 30° · rain 0.69 mm · humidity 63% · wind 8 m/s · clouds 81%

Thursday17 September 2026

🌧️31°light rain

sunrise 06:12 · sunset 18:25 · night 26° · evening 30° · rain 0.48 mm · humidity 61% · wind 8 m/s · clouds 57%

Friday18 September 2026

🌧️31°light rain

sunrise 06:13 · sunset 18:24 · night 26° · evening 30° · rain 0.54 mm · humidity 60% · wind 7 m/s · clouds 28%

Saturday19 September 2026

🌧️32°light rain

sunrise 06:13 · sunset 18:23 · night 27° · evening 31° · rain 0.12 mm · humidity 56% · wind 7 m/s · clouds 43%

UV index in San Juan - is it safe to sunbathe?

Today the UV index in San Juan is 8 (high) - unprotected fair skin can burn in about 25 minutes. SPF 30-50, a hat and sunglasses are a must. Better stay in shade between 11:00 and 15:00.

Sea temperature - San Juan

Water today

29°C

Week avg

29°C

Waves today

0.5 m

How's the water?

very warm

16-day sea temperature forecast:

5.09 29°C6.09 29°C7.09 29°C8.09 30°C9.09 30°C10.09 30°C11.09 30°C12.09 30°C13.09 30°C

Average sea temperature through the year:

Jan 27°CFeb 27°CMar 27°CApr 27°CMay 28°CJun 29°CJul 29°CAug 30°CSep 30°COct 30°CNov 29°CDec 28°C

Sea-surface temperature from marine models, updated daily. See also: where the sea is warmest right now.

Air quality and smog in San Juan

Air quality in San Juan is currently very good. Fine particulate PM2.5: 6.3 µg/m³, PM10: 19.9 µg/m³.

City	PM2.5 (µg/m³)	PM10 (µg/m³)	Air quality
San Juan	6.3	19.9	very good

Based on PM2.5 thresholds. Station readings, updated daily (last reading: 2026-09-04, 21:00).

San Juan weather through the year

Warmest, driest months on average: January, February, March, April.

Upcoming public holidays in Puerto Rico: Labour Day — 7 September · Columbus Day — 12 October · Veterans Day — 11 November.

Nearby and related places

CarolinaCaguasYaucoPonceAreciboMayagueezHumacao

FAQ - San Juan weather

What is the weather like in San Juan today?

Today it is about 32° during the day and 29° at night, light rain.

How far ahead can I check the forecast for San Juan?

This page shows a detailed 14-day forecast plus the long-term monthly climate, so you can plan both a short trip and a holiday months ahead.