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

Planting zone for 33042 — Summerland Key, FL

ZIP code 33042 (Summerland Key, Monroe County) is in USDA zone 11b: the coldest winter night averages 45 to 50 °F.

Where ZIP 33042 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 Summerland Key, 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

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Royal Palm Rs, FL — 76 miles away, 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 33042 came on Jan 9 — about the same time as the 1991–2020 average (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.

Trees 72

Shrubs 134

Wildflowers & perennials 154

Grasses 141

Vines 12

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 Summerland Key, FL.

Soil in Summerland Key, FL

The soil mapped at the center of ZIP 33042 is Isohyperthermic Udorthents — extremely gravelly sand, somewhat poorly drained.

TextureExtremely gravelly sanddrains and warms fast; dries out and needs more feeding
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Isohyperthermic udorthents-Urban land complex, 0 to 2 percent slopes, rarely 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 33042; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Summerland Key, FL

Summer high90 °Faverage high, July
Winter low66 °Faverage low, January
Hot days80days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days10,542base 50 °F — the season’s usable heat
Longest day13 h 40 mindaylight on June 21
Shortest day10 h 36 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation49.9 inper year, rain and melted snow

Average high and low, by month

60°70°80°90°100°January: average high 75 °F, low 66 °F 75°66° JanFebruary: average high 77 °F, low 68 °F 77°68° FebMarch: average high 79 °F, low 70 °F 79°70° MarApril: average high 83 °F, low 73 °F 83°73° AprMay: average high 86 °F, low 77 °F 86°77° MayJune: average high 88 °F, low 80 °F 88°80° JunJuly: average high 90 °F, low 81 °F 90°81° JulAugust: average high 90 °F, low 81 °F 90°81° AugSeptember: average high 89 °F, low 80 °F 89°80° SepOctober: average high 85 °F, low 78 °F 85°78° OctNovember: average high 80 °F, low 73 °F 80°73° NovDecember: average high 77 °F, low 69 °F 77°69° Dec

Precipitation by month inches

0″2″4″6″8″January: 1.94 in precipitation 1.9 JanFebruary: 2.33 in precipitation 2.3 FebMarch: 1.86 in precipitation 1.9 MarApril: 2.41 in precipitation 2.4 AprMay: 3.96 in precipitation 4.0 MayJune: 6.50 in precipitation 6.5 JunJuly: 5.60 in precipitation 5.6 JulAugust: 6.34 in precipitation 6.3 AugSeptember: 8.32 in precipitation 8.3 SepOctober: 5.79 in precipitation 5.8 OctNovember: 2.53 in precipitation 2.5 NovDecember: 2.33 in precipitation 2.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Key West NAS, FL (12 mi away); precipitation: Cudjoe Key 0.9 Ssw, FL (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 11b.

Florida planting zones →

Questions about 33042

What planting zone is ZIP code 33042?

ZIP code 33042 (Summerland Key, 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 33042 get?

About 49.9 inches of precipitation a year (NOAA 1991–2020 normals, Cudjoe Key 0.9 Ssw station).

How hot do summers get in Summerland Key, FL?

The average high peaks at 90 °F in July, with about 80 days a year at 90 °F or more.

What kind of soil does 33042 have?

The USDA soil survey maps Isohyperthermic Udorthents at the center of ZIP 33042: extremely gravelly sand, somewhat poorly drained, pH about 8.0 (alkaline).

Did spring come early in Summerland Key, FL in 2026?

Spring leaf-out near 33042 came on Jan 9 in 2026, about the same as the 1991–2020 average (Jan 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Summerland Key, FL?

Short-day onions: the longest day near 33042 is 13 h 40 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.