USDA Hardiness Zone 11a
Frost Dates for 33149 — Key Biscayne, Florida
NOAA 1991–2020 normals from Cape Florida, FL (6 ft), 2 miles south.
Updated
No night at or below 32°F was recorded at Cape Florida, FL in 1991–2020, so Key Biscayne has no frost dates to plan around; the coolest month, January, averages a low of 63°F.
- Winters with a freeze
- 0%
- Winters with 36°F
- 3%
- Coldest month low
- 63°F
- Hardiness zone
- 11a
32°F or below, 1991–2020
frost possible on leaves
average, January
40 to 45°F (4.4 to 7.2°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 16 observed
NOAA normal
Frost risk by date in Key Biscayne
Cape Florida, FL, 2 miles south of Key Biscayne, did not record a night at or below 32°F in 1991–2020; a 36°F night came in 3% of winters. 13 of the 158 other Florida stations behind this site's ZIP pages recorded no 32°F night either.
Freeze probabilities 1991–2020 at Cape Florida, FL, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 33149 →Compare Key Biscayne with another place →
Weather by month in Key Biscayne
August is the warmest month at Cape Florida, FL, averaging 91°F by day and 79°F at night; January is the coldest at 78°F and 63°F. Not one month recorded a 32°F night; the lowest monthly average low is 63°F.
Warmth for growing adds up to 10,482 growing degree days a year (base 50°F), more than at 99% of the 158 Florida stations. 46% of them (4,777) have built up by the end of June, and August adds the most, 1,097. Precipitation totals 55.3 inches a year, most in September (7.5") and least in February (2.0"); May to September bring 60% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 78 | 63 | 2.4 | 0% | 0 | 626 |
| Feb | 79 | 65 | 2.0 | 0% | 0 | 612 |
| Mar | 81 | 67 | 2.4 | 0% | 0 | 744 |
| Apr | 84 | 72 | 3.2 | 0% | 0 | 830 |
| May | 87 | 75 | 5.7 | 0% | 0 | 952 |
| Jun | 90 | 78 | 7.4 | 0% | 0 | 1014 |
| Jul | 91 | 79 | 5.6 | 0% | 0 | 1082 |
| Aug | 91 | 79 | 7.1 | 0% | 0 | 1097 |
| Sep | 90 | 79 | 7.5 | 0% | 0 | 1035 |
| Oct | 87 | 76 | 6.3 | 0% | 0 | 981 |
| Nov | 83 | 71 | 3.5 | 0% | 0 | 801 |
| Dec | 80 | 66 | 2.2 | 0% | 0 | 709 |
Monthly normals 1991–2020 at Cape Florida, FL (6 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Miami Beach, FL, 7 miles north of Key Biscayne, has the same share of winters with a 32°F night, 0%, and a coolest-month low 2°F colder (61°F).
When it snows in Key Biscayne, Florida
Measurable snow is rare here: only 0 of 16 winters from 1991 to 2020 recorded 0.1 inch or more at Miami Beach, FL, 7.5 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 33149 is 2 miles from Cape Florida, FL, which stands at 6 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 33149 in zone 11a, the band where the coldest night of the year averaged 40 to 45°F (4.4 to 7.2°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.