Port Isabel, Texas, sits in USDA hardiness zone 10b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor okra, black-eyed pea, tomato, and jalapeno, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Port Isabel, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Port Isabel lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Port Isabel — soil, climate, flood, and parcel records. How we handle your address.
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Port Isabel — the short answer
Port Isabel, Texas: USDA zone 10b, about 335 days between hard freezes, across 4K acres of city.
- USDA zone
- 10b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 22
- Cameron County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 23
- Cameron County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~335
- Cameron County normal — NOAA 1991–2020, nearest to this town
- City area
- 4K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Cameron County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10b is Port Isabel's average, not your lot's — a low corner or a tree line moves it. Against Port Isabel's 335-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Port Isabel
Each reading below is measured for Port Isabel itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsPort Isabel runs about 335 days between hard freezes (read from Cameron County, the closest normal to Port Isabel) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredPort Isabel sits in USDA hardiness zone 10b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Port Isabel is in
Port Isabel sits in the Western Gulf Coastal Plain — EPA Level III, inside the wider Great Plains. That is read at Port Isabel's own centroid rather than borrowed from Cameron County.
What Grows in Port Isabel
Plants matched to Port Isabel's USDA zones 10b, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in Port Isabel?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 23 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near Port Isabel
Closest first, within ~10 miles of Port Isabel. Listing isn't leaking, and distance isn't exposure.
- 7-ELEVEN STORE 40745Underground Storage Tanks · 1.1 mi
- MAVERICK MARKET 787Underground Storage Tanks · 1.2 mi
- COASTAL AUTO SERVICEUnderground Storage Tanks · 1.2 mi
- C & T QUICK STOPUnderground Storage Tanks · 1.3 mi
- CANTUS GAS AND OIL EXPRESSUnderground Storage Tanks · 1.4 mi
- HINO GAS SALESUnderground Storage Tanks · 1.4 mi
- 7-ELEVEN STORE 40747Underground Storage Tanks · 1.4 mi
- 7-ELEVEN STORE 40753Underground Storage Tanks · 1.5 mi
- LAGUNA MADRE WATER DISTRICTUnderground Storage Tanks · 1.6 mi
- WAL-MART SUPERCENTER 413Underground Storage Tanks · 1.6 mi
- WAL-MART SUPERCENTER 413Brownfields · 1.6 mi
- MURPHY USA 7590Underground Storage Tanks · 1.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Port Isabel's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Port Isabel.
Total Sites
57
within ~10 miles of Port Isabel
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Port Isabel
Severity Distribution
within ~10 miles of Port Isabel
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Port Isabel, Underground Storage Tanks runs higher than the national average — 44 sites within ~10 miles of Port Isabel. That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Port Isabel
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Port Isabel average
Your land is one point inside Port Isabel
Everything above resolves to Port Isabel as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from Cameron County’s record because no 30-year normal resolves at this city’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Port Isabel Average
Port Isabel Average
- ●USDA Zones 10b, averaged across Port Isabel
- ●One soil character for all of Port Isabel
- ●Frost dates read at Port Isabel's scale: Jan 22 to Dec 23
YOUR Parcel
- ✓Your exact zone, not Port Isabel's 10b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Port Isabel
Pull a site-specific report for your exact address in Port Isabel, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Port Isabel averages can't show:
We read public map data around Port Isabel — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Port Isabel average
How we know this about Port Isabel
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Cameron County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Port Isabel
When does frost risk typically end in Port Isabel?
The last hard freeze (28°F) in Port Isabel typically lands around Jan 22, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Feb 12.
When is the first frost in Port Isabel?
The first hard freeze (28°F) in Port Isabel typically arrives around Dec 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 9, so the watching starts about Nov 23 — about 335 days after the spring freeze cleared.
How long is the growing season in Port Isabel?
Measured between 28°F hard freezes, Port Isabel sees about 335 frost-free days — roughly Jan 22 through Dec 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 12 to Dec 9, about 300 days.
Is the soil safe to grow vegetables in Port Isabel?
The federal record around Port Isabel is a meaningful one — 57 documented sites, mostly Underground Storage Tanks entries (44), the nearest Underground Storage Tanks record about 1.1 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Port Isabel?
From about Nov 23 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Dec 23 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Dec 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Port Isabel's scale — its 10b band and its 335-day season. Your yard writes its own version of Port Isabel's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Port Isabel’s own scale
4 of the readings below were taken at Port Isabel's own scale — the 4,344 acres it covers and 57 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Port Isabel's own USDA hardiness band, zones 10bUSDA PHZM 2023
- 57 documented contamination sites on the federal record near Port Isabel, the closest Underground Storage Tanks record about 1.1 miles out from the town centreFederal environmental registers
- Port Isabel's boundary and the 4,344 acres inside itUS Census TIGER/Line 2025
- The ecoregion at Port Isabel's own centroid, the Western Gulf Coastal PlainUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Port Isabel has no normal of its own, so its county's is the closest measured readfrom Cameron County
- Soil character — no town-scale survey exists, so Port Isabel's 4,344 acres read through its county's SSURGO summaryfrom Cameron County
- The candidate plant list — Texas's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom Texas
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Cameron County
- The growing challenges every Texas grower plans around — written at state scale, so they stay on the state guidefrom Texas
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Cameron County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Port Isabel's 4,344 acreswhy one lot differs from the next →
- Which side of Port Isabel you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,344 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Port Isabel-wide figureread your own land →