Deconstruct SunSan Juan, PR: Hardiness Zone 13a & Sunlight by Season
San Juan is in USDA hardiness zone 13a. Here’s what that means for winter, plus sunrise, sunset, daylight hours and the sun’s path through the year.
Zone 13a in San Juan
On the 2023 USDA Plant Hardiness Zone Map, San Juan falls in zone 13a. That means the coldest night of a typical winter drops to between 60 and 65 °F. Perennials, shrubs and trees labeled for zone 13a or colder (a lower number) should survive the winter here.
A zone only covers winter cold. For a plant to do well it also needs the right amount of sun, and that varies far more from one corner of a yard to the next than the zone does across town.
This is not the official USDA Plant Hardiness Zone Map. Zones are derived from the official 2023 dataset, resampled to about 2 km.
Nearby cities
- Ponce, PR Zone 13a
- Mayagüez, PR Zone 13a
- Miami, FL Zone 11a
- Hollywood, FL Zone 11a
- Fort Lauderdale, FL Zone 11a
- Hialeah, FL Zone 11a
- Pompano Beach, FL Zone 11a
- Miramar, FL Zone 11a
The sun over San Juan
On the June solstice the sun rises in the northeast at 5:49 AM and climbs to 85° above the horizon at 12:26 PM. On the December solstice the noon sun reaches only 48°, so a 20-foot tree casts a noon shadow about 18 feet long. In June the same tree’s noon shadow is only 2 feet.
Sunrise, sunset & daylight by month
| Date | Sunrise | Sunset | Daylight | Noon sun |
|---|---|---|---|---|
| Jan 21 | 6:59 AM | 6:12 PM | 11h 13m | 52° |
| Feb 21 | 6:48 AM | 6:27 PM | 11h 39m | 61° |
| Mar 21 | 6:27 AM | 6:35 PM | 12h 08m | 72° |
| Apr 21 | 6:03 AM | 6:42 PM | 12h 40m | 84° |
| May 21 | 5:48 AM | 6:53 PM | 13h 04m | 88° |
| Jun 21 | 5:49 AM | 7:03 PM | 13h 14m | 85° |
| Jul 21 | 5:58 AM | 7:02 PM | 13h 04m | 88° |
| Aug 21 | 6:07 AM | 6:46 PM | 12h 39m | 84° |
| Sep 21 | 6:13 AM | 6:21 PM | 12h 08m | 72° |
| Oct 21 | 6:19 AM | 5:57 PM | 11h 38m | 61° |
| Nov 21 | 6:34 AM | 5:46 PM | 11h 12m | 52° |
| Dec 21 | 6:51 AM | 5:53 PM | 11h 02m | 48° |
Local time (Puerto Rico), including daylight saving time. “Noon sun” is the sun’s height above the horizon at solar noon.
Daylight through the year
What “full sun” means in San Juan
Full sun is 6+ hours of direct sun. In San Juan an open spot has 13.2 hours of daylight to work with in June and 11.0 in December, so a bed that clears 6 hours in summer can easily drop to part shade in winter once the low sun slips behind trees and houses.
Measure the sun in your San Juan yard
Daylight is the ceiling. Deconstruct Sun traces the trees and buildings around one exact spot and tells you its real direct-sun hours, today and at every solstice and equinox.
Questions
What hardiness zone is San Juan, PR in?
San Juan, Puerto Rico is in USDA plant hardiness zone 13a on the 2023 map. The average coldest winter night is 60 to 65 °F (15.6 to 18.3 °C).
How many hours of daylight does San Juan get?
About 13.2 hours on the June solstice (sunrise 5:49 AM, sunset 7:03 PM) and 11.0 hours on the December solstice (sunrise 6:51 AM, sunset 5:53 PM). Around the equinoxes it is close to 12 hours.
How many hours of sun does my San Juan yard get?
Up to the daylight hours above, minus whatever trees, buildings and fences block. In winter, when the sun stays low, that can be most of it. The Deconstruct Sun iPhone app measures the real direct-sun hours for one exact spot by having you trace what is around it.
When is the best time to plant in San Juan?
Zone 13a tells you which perennials survive winter, not planting dates. For timing, use your local average frost dates from your county extension office, and choose plants rated for zone 13a or colder.
Source: USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture, planthardiness.ars.usda.gov. Underlying data © PRISM Group, Oregon State University, prism.oregonstate.edu, accessed 2026-08-30. Sun times calculated for 18.405, -66.064.