Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 00685 — San Sebastian, PR

ZIP code 00685 (San Sebastian, San Sebastian County) is in USDA zone 12b: the coldest winter night averages 55 to 60 °F.

Where ZIP 00685 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.

Zone12b55 to 60 °F

Coldest night12.8 to 15.6 °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 12b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for San Sebastian, 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 Sebastian, PR is in zone 12b, 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.

Soil in San Sebastian, PR

The soil mapped at the center of ZIP 00685 is Perchas — clay, poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH4.8strongly acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter2.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Perchas clay, 12 to 20 percent slopes, eroded.

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 00685; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in San Sebastian, PR

Longest day13 h 14 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

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

0067813a

Quebradillas, PR · 7 mi

0067012b

Las Marias, PR · 7 mi

Puerto Rico planting zones →

Questions about 00685

What planting zone is ZIP code 00685?

ZIP code 00685 (San Sebastian, PR) is in USDA hardiness zone 12b on the 2023 map: the coldest night of an average winter reaches 55 to 60 °F (12.8 to 15.6 °C).

What kind of soil does 00685 have?

The USDA soil survey maps Perchas at the center of ZIP 00685: clay, poorly drained, pH about 4.8 (strongly acidic).

What kind of onions grow in San Sebastian, PR?

Short-day onions: the longest day near 00685 is 13 h 14 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.