USDA Hardiness Zone 13a
Frost Dates for 00915 — San Juan, Puerto Rico
NOAA 1991–2020 normals from San Juan L M Marin Airport, PR (9 ft), 3 miles east.
Updated
No night at or below 32°F was recorded at San Juan L M Marin Airport, PR in 1991–2020, not even 36°F, so San Juan has no frost dates to plan around; the coolest month, February, averages a low of 72°F.
- Winters with a freeze
- 0%
- Winters with 36°F
- 0%
- Coldest month low
- 72°F
- Hardiness zone
- 13a
32°F or below, 1991–2020
frost possible on leaves
average, February
60 to 65°F (15.6 to 18.3°C) coldest night
Frost risk by date in San Juan
San Juan L M Marin Airport, PR, 3 miles east of San Juan, did not record a night at or below 32°F in 1991–2020. All 25 other Puerto Rico stations behind this site's ZIP pages recorded no 32°F night either.
Freeze probabilities 1991–2020 at San Juan L M Marin Airport, PR, 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 00915 →Compare San Juan with another place →
Weather by month in San Juan
August is the warmest month at San Juan L M Marin Airport, PR, averaging 89°F by day and 78°F at night; January is the coldest at 83°F and 72°F. Not one month recorded a 32°F night; the lowest monthly average low is 72°F.
Warmth for growing adds up to 11,275 growing degree days a year (base 50°F), more than at 96% of the 25 Puerto Rico stations. 48% of them (5,392) have built up by the end of June, and August adds the most, 1,037. Precipitation totals 60.0 inches a year, most in November (7.4") and least in March (2.2"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 83 | 72 | 4.1 | 0% | 0 | 854 |
| Feb | 84 | 72 | 2.6 | 0% | 0 | 778 |
| Mar | 85 | 72 | 2.2 | 0% | 0 | 885 |
| Apr | 86 | 74 | 4.6 | 0% | 0 | 903 |
| May | 87 | 76 | 5.5 | 0% | 0 | 978 |
| Jun | 89 | 77 | 4.7 | 0% | 0 | 993 |
| Jul | 89 | 78 | 6.0 | 0% | 0 | 1028 |
| Aug | 89 | 78 | 6.3 | 0% | 0 | 1037 |
| Sep | 89 | 78 | 6.5 | 0% | 0 | 1001 |
| Oct | 89 | 77 | 5.2 | 0% | 0 | 1012 |
| Nov | 86 | 75 | 7.4 | 0% | 0 | 915 |
| Dec | 84 | 73 | 4.9 | 0% | 0 | 891 |
Monthly normals 1991–2020 at San Juan L M Marin Airport, PR (9 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, Rio Piedras Exp Stn, PR, 3 miles south of San Juan, has no 32°F night on record either, and a coolest-month low 7°F colder (65°F).
Where these figures come from
ZIP 00915 is 3 miles from San Juan L M Marin Airport, PR, which stands at 9 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 00924 (San Juan). The 2023 USDA Plant Hardiness Zone Map lists ZIP 00915 in zone 13a, the band where the coldest night of the year averaged 60 to 65°F (15.6 to 18.3°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Puerto Rico →
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.