Key Biscayne, Florida Weather
First trades stir the ceiba canopy. Day 76 of spring. Read this microseason across nine climate regions →
Key Biscayne weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Light Showers82%0.19″84°79°—
- ThursdayJun 4Showers47%5.9″81°73°-3°
- FridayJun 5Overcast22%—81°77°0°
- SaturdayJun 6Heavy Drizzle26%—83°79°+2°
- SundayJun 7Light Drizzle26%—85°81°+2°
- MondayJun 8Drizzle41%—87°82°+2°
- TuesdayJun 9Light Drizzle65%—87°82°0°
Ozone at AQI 43 — peak already passed at 1 PM under overcast skies. AQI flat over the last 6 hours (within ±4 points). Levels should ease through evening.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 8 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 43 — peak already passed at 1 PM under overcast skies. Levels should ease through evening.
- Present
- AQI 43
- UV peak
- 2.5 at earlier today
- Sky at peak
- overcast
- Projected peak
- AQI 43
PM × Wind × Precip
PM scrubbed by 4 hours of recent rain — PM2.5 down to 6.6 µg/m³, PM10 to 9.0 µg/m³.
- PM2.5/PM10
- 0.73
- Wind
- breezy
- Recent rain
- 4h 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).
The higher the clouds, the finer the weather.
- Moonrise
- 2:27 AM
- Moonset
- 1:01 PM
- In sign
- ♑︎ Capricorn
First trades stir the ceiba canopy
Key Biscayne at a glance
- Today vs. normal: 10°F below the seasonal normal for this latitude
- Last frost: January 20 (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 3, 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.
SPC Convective Outlook
Storm Prediction Center — Key Biscayne
SPC has placed Key Biscayne in the General Thunderstorms category for severe thunderstorms today.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
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
Key Biscayne's warmest month is August (~83°F mean) and its coldest is January (~67°F). Rainfall peaks in September (8.4 inches) and bottoms out in December (2.3 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 67° | 2.3″ | 5 |
| February | 69° | 2.3″ | 4 |
| March | 71° | 2.5″ | 4 |
| April | 75° | 3.4″ | 5 |
| May | 78° | 4.9″ | 6 |
| June | 81° | 7.8″ | 10 |
| July | 83° | 6.0″ | 9 |
| August | 83° | 7.5″ | 10 |
| September | 82° | 8.4″ | 11 |
| October | 79° | 6.5″ | 9 |
| November | 74° | 3.3″ | 5 |
| December | 70° | 2.3″ | 4 |
Regional context
Key Biscayne sits within a humid subtropical climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Miami, FL, Tampa, FL, Orlando, FL, Jacksonville, FL, Cape Coral, FL.
Frequently asked
- When does it freeze in Key Biscayne?
- Key Biscayne's last spring frost typically falls around mid-February, and the first fall frost arrives around mid-December.
- What is the rainy season in Key Biscayne?
- September is the wettest month with about 8.4 inches of rain on average; the city receives roughly 57 inches annually.
- What is the warmest month in Key Biscayne?
- August is typically warmest, averaging about 83°F.
- What is the coldest month in Key Biscayne?
- January is typically coldest, averaging about 67°F.
- When can I start a vegetable garden in Key Biscayne?
- 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 Key Biscayne get?
- Key Biscayne averages about 81 rainy days per year.
- What hardiness zone is Key Biscayne?
- Key Biscayne'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
Key Biscayne, Florida sits in a humid subtropical climate zone. January means hover near 67°F while July averages 83°F — a 16°F seasonal swing.
Across the year, Key Biscayne receives about 57 inches of precipitation spread over roughly 81 rainy days.
The rhythm of the year is set by latitude (25.7°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.