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

Planting zone for 33040 — Key West, FL

ZIP code 33040 (Key West, Monroe County) is in USDA zone 11b: the coldest winter night averages 45 to 50 °F.

Where ZIP 33040 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 zone11b

Same zone as on the 2012 map. 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 Key West, FL…

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: Key West, FL 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 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.

Trees 72

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °FAtlantic white cedar50 ft · blooms spring · medium shade tolerance · to −36 °F

Shrubs 134

aloe yucca15 ft · blooms early summer · medium shade tolerance · to −1 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °F

Wildflowers & perennials 154

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican century plant6 ft · blooms indeterminate · high shade tolerance · to 12 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 141

American cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fannual wildrice10 ft · blooms indeterminate · high shade tolerance · to 32 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °F

Vines 12

American wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °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 Key West, FL.

Soil in Key West, FL

The soil mapped at the center of ZIP 33040 is Islamorada — muck, very poorly drained.

TextureMucktop layer
DrainageVery poorly drainedconsider raised beds
Organic matter75%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Islamorada muck, tidal, 0 to 1 percent slopes, very 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 33040; 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
Precipitation46.4 inper year, rain and melted snow

Average high and low, by month

50°60°70°80°90°100°January: average high 75 °F, low 63 °F 75°63° JanFebruary: average high 77 °F, low 64 °F 77°64° FebMarch: average high 79 °F, low 67 °F 79°67° MarApril: average high 83 °F, low 71 °F 83°71° AprMay: average high 86 °F, low 74 °F 86°74° MayJune: average high 88 °F, low 77 °F 88°77° JunJuly: average high 90 °F, low 78 °F 90°78° JulAugust: average high 90 °F, low 79 °F 90°79° AugSeptember: average high 88 °F, low 77 °F 88°77° SepOctober: average high 85 °F, low 75 °F 85°75° OctNovember: average high 81 °F, low 70 °F 81°70° NovDecember: average high 77 °F, low 66 °F 77°66° Dec

Precipitation by month inches

0″2″4″6″8″January: 2.01 in precipitation 2.0 JanFebruary: 1.96 in precipitation 2.0 FebMarch: 1.41 in precipitation 1.4 MarApril: 2.17 in precipitation 2.2 AprMay: 3.71 in precipitation 3.7 MayJune: 4.81 in precipitation 4.8 JunJuly: 4.48 in precipitation 4.5 JulAugust: 6.13 in precipitation 6.1 AugSeptember: 8.24 in precipitation 8.2 SepOctober: 6.01 in precipitation 6.0 OctNovember: 3.28 in precipitation 3.3 NovDecember: 2.22 in precipitation 2.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Key W WFO, FL (9 mi away); precipitation: Key W WFO, FL (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 11b.

3304111b
Key West, FL · 9 mi
3304511b
Key West, FL · 9 mi
3304211b
Summerland Key, FL · 28 mi
3304311b
Big Pine Key, FL · 42 mi
3305211b
Marathon Shores, FL · 55 mi
3305111b
Key Colony Beach, FL · 58 mi
3305011b
Marathon, FL · 60 mi
3300111b
Long Key, FL · 73 mi

All 3 ZIP codes in Key West → · Florida planting zones →

Questions about 33040

What planting zone is ZIP code 33040?

ZIP code 33040 (Key West, FL) 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).

How much rain and snow does 33040 get?

About 46.4 inches of precipitation a year (NOAA 1991–2020 normals, Key W WFO station).

How hot do summers get in Key West, FL?

The average high peaks at 90 °F in July, with about 54 days a year at 90 °F or more.

What kind of soil does 33040 have?

The USDA soil survey maps Islamorada at the center of ZIP 33040: muck, very poorly drained.

What kind of onions grow in Key West, FL?

Short-day onions: the longest day near 33040 is 13 h 40 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.