San Juan, Puerto Rico Weather
San Juan hourly forecast: next 24 hours
Today's high of 86°F (30°C) is right in line with the typical August high of 88°F (31°C).
Current conditions in detail
San Juan weather tomorrow (Thursday, August 27)
Tomorrow in San Juan looks patchy rain nearby, with a high of 86° and an overnight low of 80°. There is a 57% chance of rain - plan accordingly. Winds top out near 17 mph, and the UV index reaches 12 (extreme).
San Juan 14-day forecast
About the weather in San Juan
San Juan has one of the steadier climates in our dataset. Average highs move only 3°C across the whole year - from 83°F (28°C) in January to 88°F (31°C) in July - so the practical difference between seasons here is rainfall and daylight, not warmth.
San Juan weather: quick facts
- Hottest month: July - highs near 88°F (31°C)
- Coldest month: January - highs near 83°F (28°C)
- Decade extremes (2015-2024): 97°F (36°C) high · 65°F (18°C) low
- Wettest month: September (22 rainy days) · Sunniest: June (12.2 h sun/day)
- Climate type: tropical wet-and-dry
- Annual swing: 3°C between the average warmest and coolest month · day to night: 6°C
- Months averaging 30°C or hotter: 6
- Average humidity: 77%
Temperatures through the year
Days and nights are about 6°C apart on average - narrower than about 89% of the cities we track. January is the coolest month, with highs of 83°F (28°C) and lows near 71°F (22°C). At its warmest, in July, San Juan runs to 88°F (31°C) in the afternoon and back to 77°F (25°C) by dawn. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 97°F (36°C) and the lowest daily minimum 65°F (18°C). Average highs hold at or above 30°C for 6 months of the year, May through October being the unbroken run.
Rain, sun and snow
June is the brightest month at 12.2 hours of sun a day, against an annual average of 11.1 - sunnier than 97% of the 3496 cities in our dataset. Between the average July and the average January lie 3°C, a narrower spread than all but 9% of the 3496 cities in our dataset. Precipitation concentrates in September - 6.1 inches (155 mm) on 22 days - and thins out by January.
Season by season
March through May
March through May brings hot afternoons here - highs near 86°F (30°C), nights near 73°F (23°C), and rain falls on around 49 of the 90 days. Daylight is generous - around 11.6 hours of sun a day. With the moisture factored in, afternoons feel hotter than the reading suggests - the humidity and dew point converter shows why.
June through August
June through August in San Juan is hot, with daytime highs averaging 88°F (31°C) and nights around 77°F (25°C); rain falls on around 55 of the 90 days. Daylight is generous - around 11.9 hours of sun a day.
September through November
September through November in San Juan sits firmly in the heat, with daytime highs averaging 86°F (30°C) and nights around 76°F (24°C); rain falls on around 64 of the 90 days. Daylight is generous - around 10.3 hours of sun a day.
December through February
Through December through February, San Juan runs hot: 83°F (28°C) by day, 72°F (22°C) after dark, and rain falls on around 47 of the 90 days. Daylight is generous - around 10.7 hours of sun a day.
Average temperatures in San Juan by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 83° | 71° | 14 | 2.1 in | 10.8 h/day | 77% |
| February | 83° | 72° | 15 | 2.4 in | 10.8 h/day | 75% |
| March | 84° | 72° | 15 | 2.2 in | 11.1 h/day | 73% |
| April | 85° | 73° | 16 | 3.1 in | 11.7 h/day | 74% |
| May | 87° | 75° | 17 | 3.1 in | 11.9 h/day | 75% |
| June | 89° | 76° | 17 | 2.4 in | 12.2 h/day | 75% |
| July | 88° | 77° | 19 | 3.1 in | 12.0 h/day | 76% |
| August | 88° | 77° | 19 | 3.6 in | 11.5 h/day | 78% |
| September | 88° | 77° | 22 | 6.1 in | 10.8 h/day | 81% |
| October | 87° | 76° | 22 | 4.9 in | 10.3 h/day | 82% |
| November | 85° | 74° | 20 | 5.3 in | 9.7 h/day | 82% |
| December | 83° | 73° | 18 | 2.4 in | 10.6 h/day | 79% |