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

Planting zone for 77982 — Port O Connor, TX

ZIP code 77982 (Port O Connor, Calhoun County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 4 and the first fall frost December 27.

Where ZIP 77982 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 4

First frostDec 27

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 Port O Connor, 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 Port O Connor, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostFebruary 4median — 50% chance of a later frost

Safe for tender plantsMarch 6only 10% chance of frost after

First fall frostDecember 27median — 10% chance by Nov 20

Growing season323 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 27 and returns around January 4.

From the NOAA station Port O'Connor, TX — 4 miles away, elevation 7 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 77982

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 24 – Jan 7

SpinachSow outdoors · Dec 24 – Jan 14

Broccoli, cabbageStart indoors · Nov 26 – Dec 10

Broccoli, cabbageTransplant · Jan 14 – Jan 28

Onion setsPlant outdoors · Jan 7 – Jan 21

PotatoesPlant outdoors · Jan 14 – Jan 28

LettuceSow outdoors · Jan 7 – Jan 21

Carrots, beetsSow outdoors · Jan 14 – Jan 28

TomatoesStart indoors · Dec 10 – Dec 24

TomatoesTransplant · Feb 11 – Feb 25

Peppers, eggplantStart indoors · Nov 26 – Dec 10

Peppers, eggplantTransplant · Feb 18 – Mar 4

BeansSow outdoors · Feb 11 – Feb 25

Sweet cornSow outdoors · Feb 11 – Feb 25

Cucumbers, squashSow outdoors · Feb 11 – Feb 25

Fall lettuce, spinachSow outdoors · Nov 1 – Nov 15

GarlicPlant cloves · Dec 13 – Jan 17

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 4) and first fall frost (Dec 27) 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 77982 came on Jan 15 — 6 days earlier than the 1991–2020 average (Jan 21).

average
Jan 212026
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 Port O Connor, TX.

Soil in Port O Connor, TX

The soil mapped at the center of ZIP 77982 is Portalto — fine sand, moderately well drained.

TextureFine sanddrains and warms fast; dries out and needs more feeding

pH6.1slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter0.55%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Portalto-Roemer occasionally ponded complex, 0 to 3 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 77982; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Port O Connor, TX

Summer high90 °Faverage high, August

Winter low47 °Faverage low, January

Hot days57days a year at 90 °F or more

Freezing nights4nights a year at 32 °F or less

Growing degree days7,934base 50 °F — the season’s usable heat

Longest day13 h 57 mindaylight on June 21

Shortest day10 h 20 mindaylight on December 21

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

Precipitation41.4 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: Port O'Connor, TX (4 mi away); precipitation: Pt Comfort, TX (15 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

779839b

Seadrift, TX · 13 mi

779799b

Port Lavaca, TX · 14 mi

779789b

Point Comfort, TX · 18 mi

779919b

Vanderbilt, TX · 24 mi

Collegeport, TX · 26 mi

Texas planting zones →

Questions about 77982

What planting zone is ZIP code 77982?

ZIP code 77982 (Port O Connor, 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 Port O Connor, TX?

The median last spring frost (32 °F) near 77982 is February 4; after March 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Port O'Connor station.

When is the first frost in Port O Connor, TX?

The median first fall frost near 77982 is December 27, giving a median frost-free growing season of 323 days.

When should I plant tomatoes in 77982?

Start tomato seeds indoors around Dec 10 – Dec 24 and set transplants outside around Feb 11 – Feb 25, one to three weeks after the median last frost.

How much rain and snow does 77982 get?

About 41.4 inches of precipitation a year (NOAA 1991–2020 normals, Pt Comfort station).

How hot do summers get in Port O Connor, TX?

The average high peaks at 90 °F in August, with about 57 days a year at 90 °F or more.

What kind of soil does 77982 have?

The USDA soil survey maps Portalto at the center of ZIP 77982: fine sand, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Port O Connor, TX in 2026?

Spring leaf-out near 77982 came on Jan 15 in 2026, 6 days earlier than the 1991–2020 average (Jan 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Port O Connor, TX?

Short-day onions: the longest day near 77982 is 13 h 57 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.