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

Planting zone for 33420 — West Palm Beach, FL

ZIP code 33420 (West Palm Beach, Palm Beach County) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F.

Where ZIP 33420 is

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.

Zone10b35 to 40 °F
Coldest night1.7 to 4.4 °C
Last frostrare
First frostrare
2012 zone10a

Was 10a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 10b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for West Palm Beach, 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 Palm Beach Gardens, FL — 10 miles away, elevation 20 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 33420 came on Jan 11 — about the same time as the 1991–2020 average (Jan 11).

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 10b in Florida

497 plants native to the lower 48 states, recorded in Florida, and rated by the USDA to survive 35 °F or colder — the bottom of zone 10b. Each links to its USDA PLANTS profile.

Trees 70

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 118

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 135

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 West Palm Beach, FL.

Soil in West Palm Beach, FL

The soil mapped at the center of ZIP 33420 is Matlacha — gravelly fine sand, somewhat poorly drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureGravelly fine sanddrains and warms fast; dries out and needs more feeding
pH7.0neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land, 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 33420; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in West Palm Beach, FL

Summer high90 °Faverage high, July
Winter low58 °Faverage low, January
Hot days74days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days9,443base 50 °F — the season’s usable heat
Longest day13 h 49 mindaylight on June 21
Shortest day10 h 27 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation61.8 inper year, rain and melted snow

Average high and low, by month

50°60°70°80°90°100°January: average high 75 °F, low 58 °F 75°58° JanFebruary: average high 77 °F, low 60 °F 77°60° FebMarch: average high 79 °F, low 63 °F 79°63° MarApril: average high 82 °F, low 68 °F 82°68° AprMay: average high 86 °F, low 72 °F 86°72° MayJune: average high 88 °F, low 75 °F 88°75° JunJuly: average high 90 °F, low 76 °F 90°76° JulAugust: average high 90 °F, low 77 °F 90°77° AugSeptember: average high 88 °F, low 76 °F 88°76° SepOctober: average high 85 °F, low 73 °F 85°73° OctNovember: average high 80 °F, low 66 °F 80°66° NovDecember: average high 77 °F, low 62 °F 77°62° Dec

Precipitation by month inches

0″2″4″6″8″January: 3.47 in precipitation 3.5 JanFebruary: 2.63 in precipitation 2.6 FebMarch: 3.31 in precipitation 3.3 MarApril: 3.68 in precipitation 3.7 AprMay: 4.91 in precipitation 4.9 MayJune: 8.48 in precipitation 8.5 JunJuly: 5.63 in precipitation 5.6 JulAugust: 8.68 in precipitation 8.7 AugSeptember: 7.96 in precipitation 8.0 SepOctober: 5.90 in precipitation 5.9 OctNovember: 3.62 in precipitation 3.6 NovDecember: 3.48 in precipitation 3.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: West Palm Beach Intl Airport, FL (4 mi away); precipitation: West Palm Beach Intl Airport, FL (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 10b.

3340210b
West Palm Beach, FL · <1 mi
3341910b
West Palm Beach, FL · <1 mi
3342210b
West Palm Beach, FL · <1 mi
3340110b
West Palm Beach, FL · <1 mi
3348010b
Palm Beach, FL · 2 mi
3340910b
West Palm Beach, FL · 3 mi
3340510b
West Palm Beach, FL · 3 mi
3340710b
West Palm Beach, FL · 4 mi

All 17 ZIP codes in West Palm Beach → · Florida planting zones →

Questions about 33420

What planting zone is ZIP code 33420?

ZIP code 33420 (West Palm Beach, FL) is in USDA hardiness zone 10b on the 2023 map: the coldest night of an average winter reaches 35 to 40 °F (1.7 to 4.4 °C).

How much rain and snow does 33420 get?

About 61.8 inches of precipitation a year (NOAA 1991–2020 normals, West Palm Beach Intl Airport station).

How hot do summers get in West Palm Beach, FL?

The average high peaks at 90 °F in July, with about 74 days a year at 90 °F or more.

What kind of soil does 33420 have?

The USDA soil survey maps Matlacha at the center of ZIP 33420: gravelly fine sand, somewhat poorly drained, pH about 7.0 (neutral).

Did spring come early in West Palm Beach, FL in 2026?

Spring leaf-out near 33420 came on Jan 11 in 2026, about the same as the 1991–2020 average (Jan 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in West Palm Beach, FL?

Short-day onions: the longest day near 33420 is 13 h 49 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 33420 change?

Yes. The 2012 USDA map put 33420 in zone 10a; the 2023 map puts it in zone 10b. The newer map uses 1991–2020 data and more weather stations.