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

Planting zone for 33740 — Saint Petersburg, FL

ZIP code 33740 (Saint Petersburg, Pinellas County) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F.

Where ZIP 33740 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 Saint Petersburg, 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 St Petersburg Intl Airport, FL — 2 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 33740 came on Jan 11 — 4 days earlier than the 1991–2020 average (Jan 15).

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 Saint Petersburg, FL.

Soil in Saint Petersburg, FL

The soil mapped at the center of ZIP 33740 is Matlacha — sand, somewhat poorly drained.

TextureSanddrains and warms fast; dries out and needs more feeding
pH7.2neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter0.25%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Matlacha and St. Augustine soils and Urban land.

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 33740; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saint Petersburg, FL

Summer high91 °Faverage high, August
Winter low53 °Faverage low, January
Hot days94days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days8,745base 50 °F — the season’s usable heat
Longest day13 h 55 mindaylight on June 21
Shortest day10 h 22 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation53.6 inper year, rain and melted snow

Average high and low, by month

40°50°60°70°80°90°100°January: average high 71 °F, low 53 °F 71°53° JanFebruary: average high 73 °F, low 55 °F 73°55° FebMarch: average high 77 °F, low 59 °F 77°59° MarApril: average high 82 °F, low 64 °F 82°64° AprMay: average high 87 °F, low 70 °F 87°70° MayJune: average high 90 °F, low 75 °F 90°75° JunJuly: average high 90 °F, low 76 °F 90°76° JulAugust: average high 91 °F, low 76 °F 91°76° AugSeptember: average high 89 °F, low 75 °F 89°75° SepOctober: average high 84 °F, low 70 °F 84°70° OctNovember: average high 77 °F, low 61 °F 77°61° NovDecember: average high 73 °F, low 56 °F 73°56° Dec

Precipitation by month inches

0″2″4″6″8″10″January: 2.62 in precipitation 2.6 JanFebruary: 2.38 in precipitation 2.4 FebMarch: 2.43 in precipitation 2.4 MarApril: 2.57 in precipitation 2.6 AprMay: 2.73 in precipitation 2.7 MayJune: 8.86 in precipitation 8.9 JunJuly: 9.73 in precipitation 9.7 JulAugust: 8.83 in precipitation 8.8 AugSeptember: 6.40 in precipitation 6.4 SepOctober: 2.49 in precipitation 2.5 OctNovember: 1.64 in precipitation 1.6 NovDecember: 2.94 in precipitation 2.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: St Petersburg Intl Airport, FL (2 mi away); precipitation: St Petersburg Intl Airport, FL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

3373110b
Saint Petersburg, FL · <1 mi
3373210b
Saint Petersburg, FL · <1 mi
3373410a
Saint Petersburg, FL · <1 mi
3373610b
Saint Petersburg, FL · <1 mi
3373810b
Saint Petersburg, FL · <1 mi
3374110b
Saint Petersburg, FL · <1 mi
3374210b
Saint Petersburg, FL · <1 mi
3374310b
Saint Petersburg, FL · <1 mi

All 30 ZIP codes in Saint Petersburg → · Florida planting zones →

Questions about 33740

What planting zone is ZIP code 33740?

ZIP code 33740 (Saint Petersburg, 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 33740 get?

About 53.6 inches of precipitation a year (NOAA 1991–2020 normals, St Petersburg Intl Airport station).

How hot do summers get in Saint Petersburg, FL?

The average high peaks at 91 °F in August, with about 94 days a year at 90 °F or more.

What kind of soil does 33740 have?

The USDA soil survey maps Matlacha at the center of ZIP 33740: sand, somewhat poorly drained, pH about 7.2 (neutral).

Did spring come early in Saint Petersburg, FL in 2026?

Spring leaf-out near 33740 came on Jan 11 in 2026, 4 days earlier than the 1991–2020 average (Jan 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Saint Petersburg, FL?

Short-day onions: the longest day near 33740 is 13 h 55 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 33740 change?

Yes. The 2012 USDA map put 33740 in zone 10a; the 2023 map puts it in zone 10b. The newer map uses 1991–2020 data and more weather stations.