Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for San Juan, PR

San Juan, PR is in USDA zones 13a to 13b across its 36 ZIP codes.

San Juan on the zone map

Outlined: its 17 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zones13a–13b60 to 70 °F
ZIP codes36
Last frostrare
First frostrare
Growing seasonall year

13a 22 ZIPs   13b 14 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for San Juan, PR…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates

Frost is rare or absent here: San Juan, PR is in zone 13b, where the coldest night of a typical winter stays above freezing. Cool-season vegetables grow best from fall through spring; summer heat, not frost, is the limit.

Native plants for zone 13a in Puerto Rico

153 plants native to Puerto Rico, recorded in Puerto Rico, and rated by the USDA to survive 60 °F or colder — the bottom of zone 13a. Each links to its USDA PLANTS profile.

Trees 41

achiotillo52 ft · blooms early spring · high shade tolerance · to 40 °Fbastard redwood15 ft · to 40 °Fbulletwood100 ft · blooms summer · low shade tolerance · to 52 °Fbullwood100 ft · blooms summer · high shade tolerance · to 40 °Fcabbagebark tree90 ft · blooms summer · high shade tolerance · to 32 °Fcandletree115 ft · blooms early summer · medium shade tolerance · to 50 °F

Shrubs 46

American muskwood10 ft · blooms spring · to 40 °FAntilles calophyllum65 ft · blooms late spring · medium shade tolerance · to 36 °Fbastard stopper43 ft · blooms summer · high shade tolerance · to 40 °Fblack mangrove30 ft · blooms indeterminate · high shade tolerance · to 10 °Fbroadleaf caper33 ft · to 40 °Fbroomstick25 ft · blooms spring · medium shade tolerance · to 40 °F

Wildflowers & perennials 31

bayhops1 ft · blooms indeterminate · medium shade tolerance · to 17 °Fbroadleaf arrowhead5 ft · blooms late spring · high shade tolerance · to −33 °FCanadian horseweed5 ft · blooms indeterminate · high shade tolerance · to 52 °Fcinnamon fern5 ft · blooms spring · low shade tolerance · to −33 °Fclimbing dayflower1 ft · blooms summer · low shade tolerance · to 47 °Fcommon duckmeatblooms late summer · medium shade tolerance · to −38 °F

Grasses 34

American cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °Fbroadleaf carpetgrass1 ft · blooms spring · high shade tolerance · to −3 °Fbroomsedge bluestem3 ft · blooms late spring · high shade tolerance · to −18 °Fbrownseed paspalum3 ft · blooms summer · medium shade tolerance · to 7 °Fbushy bluestem6 ft · blooms late summer · high shade tolerance · to −23 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in San Juan, PR.

Climate in San Juan, PR

Longest day13 h 14 mindaylight on June 21
Shortest day11 h 01 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Daylight is calculated from latitude.

ZIP codes in San Juan

0090113b
65 to 70 °F
0090213b
65 to 70 °F
0090613b
65 to 70 °F
0090713b
65 to 70 °F
0090813b
65 to 70 °F
0090913b
65 to 70 °F
0091013b
65 to 70 °F
0091113b
65 to 70 °F
0091213b
65 to 70 °F
0091313b
65 to 70 °F
0091413b
65 to 70 °F
0091513a
60 to 65 °F
0091613b
65 to 70 °F
0091713a
60 to 65 °F
0091813a
60 to 65 °F
0091913a
60 to 65 °F
0092013a
60 to 65 °F
0092113a
60 to 65 °F
0092213a
60 to 65 °F
0092313a
60 to 65 °F
0092413a
60 to 65 °F
0092513a
60 to 65 °F
0092613a
60 to 65 °F
0092713a
60 to 65 °F
0092813a
60 to 65 °F
0092913a
60 to 65 °F
0093013a
60 to 65 °F
0093113a
60 to 65 °F
0093313a
60 to 65 °F
0093513a
60 to 65 °F
0093613a
60 to 65 °F
0093713b
65 to 70 °F
0093913a
60 to 65 °F
0094013b
65 to 70 °F
0095513a
60 to 65 °F
0097513a
60 to 65 °F

Puerto Rico planting zones →

Questions about San Juan

What planting zone is San Juan, PR?

San Juan, PR is in USDA hardiness zones 13a to 13b on the 2023 map (13a: 60 to 65 °F; 13b: 65 to 70 °F).

What kind of onions grow in San Juan, PR?

Short-day onions: the longest day is 13 h 14 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.