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

Planting zone for 33149 — Key Biscayne, FL

ZIP code 33149 (Key Biscayne, Miami-Dade County) is in USDA zone 11a: the coldest winter night averages 40 to 45 °F.

Where ZIP 33149 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.

Zone11a40 to 45 °F
Coldest night4.4 to 7.2 °C
Last frostrare
First frostrare
2012 zone11a

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 11a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Key Biscayne, 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 Perrine 4w, FL — 19 miles away, elevation 10 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 33149 came on Jan 10 — about the same time as the 1991–2020 average (Jan 10).

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 11a in Florida

518 plants native to the lower 48 states, recorded in Florida, and rated by the USDA to survive 40 °F or colder — the bottom of zone 11a. 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 138

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 Biscayne, FL.

Soil in Key Biscayne, FL

The soil mapped at the center of ZIP 33149 is Baggs Cape — fine sand, somewhat poorly drained.

TextureFine sanddrains and warms fast; dries out and needs more feeding
pH7.6slightly alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Baggs Cape fine sand-Urban land complex, 0 to 2 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 33149; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Key Biscayne, FL

Summer high91 °Faverage high, July
Winter low63 °Faverage low, January
Hot days55days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days10,482base 50 °F — the season’s usable heat
Longest day13 h 45 mindaylight on June 21
Shortest day10 h 32 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation55.3 inper year, rain and melted snow

Average high and low, by month

50°60°70°80°90°100°January: average high 78 °F, low 63 °F 78°63° JanFebruary: average high 79 °F, low 65 °F 79°65° FebMarch: average high 81 °F, low 67 °F 81°67° MarApril: average high 84 °F, low 72 °F 84°72° AprMay: average high 87 °F, low 75 °F 87°75° MayJune: average high 90 °F, low 78 °F 90°78° JunJuly: average high 91 °F, low 79 °F 91°79° JulAugust: average high 91 °F, low 79 °F 91°79° AugSeptember: average high 90 °F, low 79 °F 90°79° SepOctober: average high 87 °F, low 76 °F 87°76° OctNovember: average high 83 °F, low 71 °F 83°71° NovDecember: average high 80 °F, low 66 °F 80°66° Dec

Precipitation by month inches

0″2″4″6″8″January: 2.44 in precipitation 2.4 JanFebruary: 2.00 in precipitation 2.0 FebMarch: 2.37 in precipitation 2.4 MarApril: 3.17 in precipitation 3.2 AprMay: 5.67 in precipitation 5.7 MayJune: 7.37 in precipitation 7.4 JunJuly: 5.64 in precipitation 5.6 JulAugust: 7.05 in precipitation 7.0 AugSeptember: 7.54 in precipitation 7.5 SepOctober: 6.33 in precipitation 6.3 OctNovember: 3.51 in precipitation 3.5 NovDecember: 2.24 in precipitation 2.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cape Florida, FL (3 mi away); precipitation: Cape Florida, FL (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 11a.

3312911a
Miami, FL · 4 mi
3313111a
Miami, FL · 4 mi
3310911a
Miami Beach, FL · 4 mi
3319511a
Miami, FL · 4 mi
3313211a
Miami, FL · 4 mi
3313011a
Miami, FL · 4 mi
3313311a
Miami, FL · 5 mi
3310211a
Miami, FL · 5 mi

Florida planting zones →

Questions about 33149

What planting zone is ZIP code 33149?

ZIP code 33149 (Key Biscayne, FL) is in USDA hardiness zone 11a on the 2023 map: the coldest night of an average winter reaches 40 to 45 °F (4.4 to 7.2 °C).

How much rain and snow does 33149 get?

About 55.3 inches of precipitation a year (NOAA 1991–2020 normals, Cape Florida station).

How hot do summers get in Key Biscayne, FL?

The average high peaks at 91 °F in July, with about 55 days a year at 90 °F or more.

What kind of soil does 33149 have?

The USDA soil survey maps Baggs Cape at the center of ZIP 33149: fine sand, somewhat poorly drained, pH about 7.6 (slightly alkaline).

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

Spring leaf-out near 33149 came on Jan 10 in 2026, about the same as the 1991–2020 average (Jan 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Key Biscayne, FL?

Short-day onions: the longest day near 33149 is 13 h 45 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.