Guaynabo, Puerto Rico Weather
First trades stir the ceiba canopy. Day 77 of spring. Read this microseason across nine climate regions →
Guaynabo weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Light Drizzle88%0.05″89°75°—
- FridayJun 5Drizzle79%0.07″90°75°+1°
- SaturdayJun 6Drizzle91%0.06″90°74°0°
- SundayJun 7Light Drizzle81%0.04″89°76°-1°
- MondayJun 8Light Drizzle40%—90°78°+1°
- TuesdayJun 9Overcast18%—91°77°+1°
- WednesdayJun 10Overcast——87°77°-4°
AQI 27 (Good), driven by Ozone. AQI down 16 over the last 6 hours — air quality is improving sharply.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
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
- 1:56 AM
- Moonset
- 1:14 PM
- In sign
- ♑︎ Capricorn
First trades stir the ceiba canopy
Guaynabo at a glance
- Today vs. normal: 20°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
Guaynabo's warmest month is August (~85°F mean) and its coldest is January (~69°F). Rainfall peaks in September (8.2 inches) and bottoms out in February (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
Guaynabo sits within a varied climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: San Juan, PR, Aguadilla, PR, Bayamón, PR, Carolina, PR, Arecibo, PR.
Frequently asked
- When does it freeze in Guaynabo?
- Guaynabo's last spring frost typically falls around mid-February, and the first fall frost arrives around mid-December.
- What is the rainy season in Guaynabo?
- September is the wettest month with about 8.2 inches of rain on average; the city receives roughly 57 inches annually.
- What is the warmest month in Guaynabo?
- August is typically warmest, averaging about 85°F.
- What is the coldest month in Guaynabo?
- January is typically coldest, averaging about 69°F.
- When can I start a vegetable garden in Guaynabo?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-February); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Guaynabo get?
- Guaynabo averages about 184 rainy days per year.
- What hardiness zone is Guaynabo?
- Guaynabo's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Guaynabo, Puerto Rico sits in a varied climate zone. January means hover near 69°F while July averages 84°F — a 15°F seasonal swing.
Across the year, Guaynabo receives about 57 inches of precipitation spread over roughly 184 rainy days.
The rhythm of the year is set by latitude (18.4°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.