San Juan, Puerto Rico Weather
First trades stir the ceiba canopy. Day 77 of spring. Read this microseason across nine climate regions →
San Juan weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Light Rain100%0.11″89°75°—
- FridayJun 5Light Drizzle74%0.03″90°75°+1°
- SaturdayJun 6Light Drizzle88%0.04″90°76°0°
- SundayJun 7Light Drizzle78%0.05″88°76°-2°
- MondayJun 8Light Drizzle35%0.01″91°77°+3°
- TuesdayJun 9Light Drizzle15%0.01″89°77°-2°
- WednesdayJun 10Overcast——88°77°-1°
PM scrubbed by 3 hours of recent rain — PM2.5 down to 15.3 µg/m³, PM10 to 32.2 µg/m³. AQI flat over the last 6 hours (within ±3 points).
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM scrubbed by 3 hours of recent rain — PM2.5 down to 15.3 µg/m³, PM10 to 32.2 µg/m³.
- PM2.5/PM10
- 0.48
- Wind
- light
- Recent rain
- 3h in last 6h
- Pattern
- washed out
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 1:55 AM
- Moonset
- 1:13 PM
- In sign
- ♒︎ Aquarius
First trades stir the ceiba canopy
San Juan at a glance
- Today vs. normal: 13°F below the seasonal normal for this latitude
- Last frost: December 7 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | lettuce, peas, spinach, radishes | — |
| March | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| April | tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | — | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
August brings San Juan's warmest temperatures (~85°F mean) while January delivers the coldest (~69°F). September sees peak rainfall at 8.2 inches, and February records the driest conditions at 2.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 69° | 2.1″ | 7 |
| February | 71° | 2.0″ | 7 |
| March | 73° | 2.2″ | 7 |
| April | 77° | 3.3″ | 11 |
| May | 80° | 4.8″ | 16 |
| June | 83° | 7.9″ | 25 |
| July | 84° | 5.8″ | 19 |
| August | 85° | 6.9″ | 23 |
| September | 83° | 8.2″ | 25 |
| October | 81° | 7.9″ | 25 |
| November | 76° | 3.3″ | 11 |
| December | 72° | 2.5″ | 8 |
Regional context
San Juan belongs to a varied climate region — part of a cohort sharing similar temperature ranges, seasonal patterns, and growing conditions with nearby cities.
Similar climates: Aguadilla, PR, Bayamón, PR, Carolina, PR, Arecibo, PR, Ponce, PR.
Naturalist notes
May brings the peak flowering period for flamboyant trees, their orange-red blooms creating canopies of color across the city.
Trade winds carry migrating warblers northward during late April and early May, as these small birds follow ancient flyways toward North American breeding grounds.
Frequently asked
- When does it freeze in San Juan?
- San Juan's last spring frost typically occurs around mid-February, while the first fall frost arrives around mid-December.
- What is the rainy season in San Juan?
- September records the highest rainfall with about 8.2 inches on average; the city receives roughly 57 inches annually.
- What is the warmest month in San Juan?
- August typically brings the warmest weather, averaging about 85°F.
- What is the coldest month in San Juan?
- January typically delivers the coldest temperatures, averaging about 69°F.
- When can I start a vegetable garden in San Juan?
- Cool-season crops (peas, lettuce) can be planted around the last spring frost (mid-February); warm-season crops (tomatoes, peppers) should wait until 1–2 weeks after.
- How many rainy days does San Juan get?
- San Juan records about 184 rainy days per year on average.
- What hardiness zone is San Juan?
- San Juan's USDA hardiness zone depends on its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
San Juan, Puerto Rico experiences a varied climate zone. Temperatures hover near 69°F during January while July averages 84°F — creating a 15°F seasonal swing.
Throughout the year, San Juan receives about 57 inches of precipitation distributed across roughly 184 rainy days.
Latitude (18.4°N), proximity to large water bodies, and elevation determine the rhythm of the year — shaping what grows here, when frost occurs, and the daily weather patterns.