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

Planting zone for Port Arthur, TX

Port Arthur, TX is in USDA zone 9b across its 4 ZIP codes. The median last spring frost is February 14 and the first fall frost December 7.

Port Arthur on the zone map

Outlined: its 2 ZIP code areas · 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
ZIP codes4
Last frostFeb 14
First frostDec 7
Growing season301 days

9b 4 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Arthur, TX

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 14median — 50% chance of a later frost
Safe for tender plantsMarch 13only 10% chance of frost after
First fall frostDecember 7median — 10% chance by Nov 15
Growing season301 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 28 and returns around January 1.

From the NOAA station Port Arthur Se Tx Airport, TX, elevation 16 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 Port Arthur

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 3 – Jan 17
SpinachSow outdoors · Jan 3 – Jan 24
Broccoli, cabbageStart indoors · Dec 6 – Dec 20
Broccoli, cabbageTransplant · Jan 24 – Feb 7
Onion setsPlant outdoors · Jan 17 – Jan 31
PotatoesPlant outdoors · Jan 24 – Feb 7
LettuceSow outdoors · Jan 17 – Jan 31
Carrots, beetsSow outdoors · Jan 24 – Feb 7
TomatoesStart indoors · Dec 20 – Jan 3
TomatoesTransplant · Feb 21 – Mar 7
Peppers, eggplantStart indoors · Dec 6 – Dec 20
Peppers, eggplantTransplant · Feb 28 – Mar 14
BeansSow outdoors · Feb 21 – Mar 7
Sweet cornSow outdoors · Feb 21 – Mar 7
Cucumbers, squashSow outdoors · Feb 21 – Mar 7
Fall lettuce, spinachSow outdoors · Oct 12 – Oct 26
GarlicPlant cloves · Nov 23 – Dec 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 14) and first fall frost (Dec 7) 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 77640 came on Jan 11 — 13 days earlier than the 1991–2020 average (Jan 24).

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.

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 elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °FArizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °F

Shrubs 142

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Faloe yucca15 ft · blooms early summer · medium shade tolerance · to −1 °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 snowbell10 ft · blooms spring · medium shade tolerance · to −16 °F

Wildflowers & perennials 212

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican 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 licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 197

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °FArizona fescue2 ft · blooms late spring · high shade tolerance · to −23 °FArizona threeawn2 ft · blooms mid summer · high shade tolerance · to −3 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °F

Vines 14

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican 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 °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 Port Arthur, TX.

Soil in Port Arthur, TX

The center of ZIP 77640 is mapped as Urban land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 77640; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Port Arthur, TX

Summer high93 °Faverage high, July
Winter low44 °Faverage low, January
Hot days93days a year at 90 °F or more
Freezing nights8nights a year at 32 °F or less
Growing degree days7,445base 50 °F — the season’s usable heat
Longest day14 h 04 mindaylight on June 21
Shortest day10 h 13 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation59.8 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 64 °F, low 44 °F 64°44° JanFebruary: average high 67 °F, low 48 °F 67°48° FebMarch: average high 73 °F, low 53 °F 73°53° MarApril: average high 79 °F, low 60 °F 79°60° AprMay: average high 86 °F, low 67 °F 86°67° MayJune: average high 91 °F, low 73 °F 91°73° JunJuly: average high 93 °F, low 75 °F 93°75° JulAugust: average high 93 °F, low 74 °F 93°74° AugSeptember: average high 90 °F, low 71 °F 90°71° SepOctober: average high 82 °F, low 61 °F 82°61° OctNovember: average high 72 °F, low 52 °F 72°52° NovDecember: average high 66 °F, low 46 °F 66°46° Dec

Precipitation by month inches

0″2″4″6″January: 5.42 in precipitation 5.4 JanFebruary: 3.25 in precipitation 3.3 FebMarch: 3.32 in precipitation 3.3 MarApril: 3.32 in precipitation 3.3 AprMay: 4.76 in precipitation 4.8 MayJune: 6.60 in precipitation 6.6 JunJuly: 6.17 in precipitation 6.2 JulAugust: 6.79 in precipitation 6.8 AugSeptember: 6.14 in precipitation 6.1 SepOctober: 5.54 in precipitation 5.5 OctNovember: 3.85 in precipitation 3.9 NovDecember: 4.64 in precipitation 4.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Port Arthur Se Tx Airport, TX (7 mi away); precipitation: Port Arthur City, TX (2 mi away). Daylight is calculated from latitude.

ZIP codes in Port Arthur

776409b
25 to 30 °F
776419b
25 to 30 °F
776429b
25 to 30 °F
776439b
25 to 30 °F

Texas planting zones →

Questions about Port Arthur

What planting zone is Port Arthur, TX?

Port Arthur, TX is in USDA hardiness zone 9b on the 2023 map (9b: 25 to 30 °F).

When is the last frost in Port Arthur, TX?

The median last spring frost is February 14 and the median first fall frost is December 7 (NOAA 1991–2020 normals, Port Arthur Se Tx Airport station).

When can I plant a garden in Port Arthur, TX?

Cool-season crops like peas and spinach go in around Jan 3 – Jan 24; tomatoes, peppers, beans and squash after about Feb 21, once frost risk has passed.

What kind of onions grow in Port Arthur, TX?

Short-day onions: the longest day is 14 h 04 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

How much rain and snow does Port Arthur, TX get?

About 59.8 inches of precipitation a year (NOAA 1991–2020 normals).