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

Planting zone for 00631 — Castaner, PR

ZIP code 00631 (Castaner, Lares County) is in USDA zone 11b: the coldest winter night averages 45 to 50 °F.

Where ZIP 00631 is

Outlined: the ZIP code area · 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.

Zone11b45 to 50 °F
Coldest night7.2 to 10 °C
Last frostrare
First frostrare
2012 zone—

The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 11b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Castaner, 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: Castaner, PR is in zone 11b, 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 11b in Puerto Rico

145 plants native to Puerto Rico, recorded in Puerto Rico, and rated by the USDA to survive 45 °F or colder — the bottom of zone 11b. Each links to its USDA PLANTS profile.

Trees 36

achiotillo52 ft · blooms early spring · high shade tolerance · to 40 °Fbastard redwood15 ft · to 40 °Fbullwood100 ft · blooms summer · high shade tolerance · to 40 °Fcabbagebark tree90 ft · blooms summer · high shade tolerance · to 32 °Fcobana negra50 ft · blooms spring · to 40 °Fcorcho bobo30 ft · blooms early spring · to 40 °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 29

bayhops1 ft · blooms indeterminate · medium shade tolerance · to 17 °Fbroadleaf arrowhead5 ft · blooms late spring · high shade tolerance · to −33 °Fcinnamon fern5 ft · blooms spring · low shade tolerance · to −33 °Fcommon duckmeatblooms late summer · medium shade tolerance · to −38 °Fcommon maidenhair1.7 ft · blooms summer · low shade tolerance · to −33 °Fcoon's tailblooms summer · medium shade tolerance · to −38 °F

Grasses 33

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 Castaner, PR.

Soil in Castaner, PR

The soil mapped at the center of ZIP 00631 is Morado — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH6.8neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.91%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Morado clay loam, 40 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 00631; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Castaner, PR

Longest day13 h 13 mindaylight on June 21
Shortest day11 h 02 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.

Nearby ZIP codes

7 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

0060111b
Adjuntas, PR · 5 mi
0061112a
Angeles, PR · 7 mi
0066912b
Lares, PR · 7 mi
0060612b
Maricao, PR · 7 mi
0069812b
Yauco, PR · 8 mi
0064112a
Utuado, PR · 10 mi
0065613a
Guayanilla, PR · 10 mi
0063712b
Sabana Grande, PR · 11 mi

Puerto Rico planting zones →

Questions about 00631

What planting zone is ZIP code 00631?

ZIP code 00631 (Castaner, PR) is in USDA hardiness zone 11b on the 2023 map: the coldest night of an average winter reaches 45 to 50 °F (7.2 to 10 °C).

What kind of soil does 00631 have?

The USDA soil survey maps Morado at the center of ZIP 00631: clay loam, well drained, pH about 6.8 (neutral).

What kind of onions grow in Castaner, PR?

Short-day onions: the longest day near 00631 is 13 h 13 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.