Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 77623 — High Island, TX

ZIP code 77623 (High Island, Galveston County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 12 and the first fall frost December 6.

Where ZIP 77623 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.

Zone9b25 to 30 °F

Coldest night−3.9 to −1.1 °C

Last frostFeb 12

First frostDec 6

2012 zone9b

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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for High Island, TX…

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 in High Island, TX

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostFebruary 12median — 50% chance of a later frost

Safe for tender plantsMarch 10only 10% chance of frost after

First fall frostDecember 6median — 10% chance by Nov 16

Growing season302 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 25 and returns around December 31.

From the NOAA station Anahuac, TX — 20 miles away, elevation 23 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 77623

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 1 – Jan 15

SpinachSow outdoors · Jan 1 – Jan 22

Broccoli, cabbageStart indoors · Dec 4 – Dec 18

Broccoli, cabbageTransplant · Jan 22 – Feb 5

Onion setsPlant outdoors · Jan 15 – Jan 29

PotatoesPlant outdoors · Jan 22 – Feb 5

LettuceSow outdoors · Jan 15 – Jan 29

Carrots, beetsSow outdoors · Jan 22 – Feb 5

TomatoesStart indoors · Dec 18 – Jan 1

TomatoesTransplant · Feb 19 – Mar 5

Peppers, eggplantStart indoors · Dec 4 – Dec 18

Peppers, eggplantTransplant · Feb 26 – Mar 12

BeansSow outdoors · Feb 19 – Mar 5

Sweet cornSow outdoors · Feb 19 – Mar 5

Cucumbers, squashSow outdoors · Feb 19 – Mar 5

Fall lettuce, spinachSow outdoors · Oct 11 – Oct 25

GarlicPlant cloves · Nov 22 – Dec 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 12) and first fall frost (Dec 6) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 77623 came on Jan 15 — 8 days earlier than the 1991–2020 average (Jan 23).

average
Jan 232026
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 9b in Texas

646 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 25 °F or colder — the bottom of zone 9b. Each links to its USDA PLANTS profile.

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 High Island, TX.

Soil in High Island, TX

The soil mapped at the center of ZIP 77623 is Francitas — clay, somewhat poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter5.5%high

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Francitas clay, 0 to 1 percent slopes, frequently flooded, occasionally ponded.

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 77623; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in High Island, TX

Summer high92 °Faverage high, August

Winter low43 °Faverage low, January

Hot days68days a year at 90 °F or more

Freezing nights11nights a year at 32 °F or less

Growing degree days7,049base 50 °F — the season’s usable heat

Longest day14 h 03 mindaylight on June 21

Shortest day10 h 15 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation59.7 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Anahuac, TX (20 mi away); precipitation: Anahuac, TX (20 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.

Port Bolivar, TX · 17 mi

Wallisville, TX · 25 mi

Texas planting zones →

Questions about 77623

What planting zone is ZIP code 77623?

ZIP code 77623 (High Island, TX) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in High Island, TX?

The median last spring frost (32 °F) near 77623 is February 12; after March 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Anahuac station.

When is the first frost in High Island, TX?

The median first fall frost near 77623 is December 6, giving a median frost-free growing season of 302 days.

When should I plant tomatoes in 77623?

Start tomato seeds indoors around Dec 18 – Jan 1 and set transplants outside around Feb 19 – Mar 5, one to three weeks after the median last frost.

How much rain and snow does 77623 get?

About 59.7 inches of precipitation a year (NOAA 1991–2020 normals, Anahuac station).

How hot do summers get in High Island, TX?

The average high peaks at 92 °F in August, with about 68 days a year at 90 °F or more.

What kind of soil does 77623 have?

The USDA soil survey maps Francitas at the center of ZIP 77623: clay, somewhat poorly drained, pH about 7.9 (alkaline).

Did spring come early in High Island, TX in 2026?

Spring leaf-out near 77623 came on Jan 15 in 2026, 8 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in High Island, TX?

Short-day onions: the longest day near 77623 is 14 h 03 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.