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

Planting zone for Key West, FL

Key West, FL is in USDA zone 11b across its 3 ZIP codes.

Key West on the zone map

Outlined: its 1 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.

Zone11b45 to 50 °F

ZIP codes3

Last frostrare

First frostrare

Growing seasonall year

11b 3 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Everglades, FL, elevation 7 ft) the median growing season is 365 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

When spring arrived in 2026

In 2026, spring leaf-out near 33041 came on Jan 9 — about the same time as the 1991–2020 average (Jan 9).

average
Jan 92026
Jan 9

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 11b in Florida

521 plants native to the lower 48 states, recorded in Florida, and rated by the USDA to survive 45 °F or colder — the bottom of zone 11b. Each links to its USDA PLANTS profile.

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 Key West, FL.

Soil in Key West, FL

The soil mapped at the center of ZIP 33041 is Pennekamp — gravelly muck, moderately well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureGravelly mucktop layer

DrainageModerately well drainednatural drainage class

Organic matter75%high

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Urban land, 0 to 2 percent slopes, frequently flooded.

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 33041; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Key West, FL

Summer high90 °Faverage high, July

Winter low63 °Faverage low, January

Hot days54days a year at 90 °F or more

Freezing nights0nights a year at 32 °F or less

Growing degree days9,993base 50 °F — the season’s usable heat

Longest day13 h 40 mindaylight on June 21

Shortest day10 h 37 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation46.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Key W WFO, FL (within 1 mile); precipitation: Key West 0.5 Sw, FL (within 1 mile). Daylight is calculated from latitude.