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USDA hardiness zone lookup

Weslaco (78596) — USDA Zone 9b

Weslaco, Texas · 312-day growing season

Frost dates and growing season for 78596

USDA hardiness zoneZone 9b
Average last spring frostFebruary 5
Average first fall frostDecember 14
Growing season length~312 days
Temperature range (F)20 to 30°F
Temperature range (C)-7 to -1°C

These are 50%-probability averages modeled from this ZIP's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by February 5, but in a colder-than-average year it can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Weslaco

Weslaco, Texas sits in USDA Zone 9b, with roughly 312 frost-free days between an average last spring frost around February 5 and a first fall frost around December 14. That is a near year-round season — the limiting factor is summer heat, not frost, so schedule cool-season crops for winter and protect tender ones from extreme highs.

What grows in Weslaco

Weslaco falls in USDA Zone 9b, which means the same hardiness constraints apply as the full Zone 9 guide. Vegetables, herbs, and fruit trees rated to Zone 9b (or hardier) will overwinter here in a typical year.

What to plant in Weslaco this week

Weslaco is in the winter hold — outdoor planting is on pause. Use this time to plan, order seeds, and prep beds. Tomato and pepper seeds can start indoors 6-10 weeks before your last frost (February 5).

Full planting calendar for Weslaco

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 9 averages:

Local microclimate notes

Zone tables give you the average — but Weslacogardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record (the last time you actually got frost damage) is more accurate than any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.

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