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

Planting zone for 78236 — Jbsa Lackland, TX

ZIP code 78236 (Jbsa Lackland, Bexar County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 22 and the first fall frost December 2.

Where ZIP 78236 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.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostFeb 22

First frostDec 2

2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Jbsa Lackland, 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 Jbsa Lackland, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostFebruary 22median — 50% chance of a later frost

Safe for tender plantsMarch 12only 10% chance of frost after

First fall frostDecember 2median — 10% chance by Nov 13

Growing season284 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 1 and returns around December 16.

From the NOAA station San Antonio Kelly AFB, TX — 2 miles away, elevation 682 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 78236

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 11 – Jan 25

SpinachSow outdoors · Jan 11 – Feb 1

Broccoli, cabbageStart indoors · Dec 14 – Dec 28

Broccoli, cabbageTransplant · Feb 1 – Feb 15

Onion setsPlant outdoors · Jan 25 – Feb 8

PotatoesPlant outdoors · Feb 1 – Feb 15

LettuceSow outdoors · Jan 25 – Feb 8

Carrots, beetsSow outdoors · Feb 1 – Feb 15

TomatoesStart indoors · Dec 28 – Jan 11

TomatoesTransplant · Mar 1 – Mar 15

Peppers, eggplantStart indoors · Dec 14 – Dec 28

Peppers, eggplantTransplant · Mar 8 – Mar 22

BeansSow outdoors · Mar 1 – Mar 15

Sweet cornSow outdoors · Mar 1 – Mar 15

Cucumbers, squashSow outdoors · Mar 1 – Mar 15

Fall lettuce, spinachSow outdoors · Oct 7 – Oct 21

GarlicPlant cloves · Nov 18 – Dec 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 22) and first fall frost (Dec 2) 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 78236 came on Jan 20 — 4 days earlier than the 1991–2020 average (Jan 24).

average
Jan 242026
Jan 20

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 9a in Texas

640 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. 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 Jbsa Lackland, TX.

Soil in Jbsa Lackland, TX

The soil mapped at the center of ZIP 78236 is Houston Black — gravelly clay, moderately well drained.

TextureGravelly clayholds water and nutrients; slow to drain and warm up

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter3%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classprime farmlandUSDA classification

Map unit: Houston Black gravelly clay, 1 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 78236; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Jbsa Lackland, TX

Summer high97 °Faverage high, August

Winter low41 °Faverage low, January

Hot days141days a year at 90 °F or more

Freezing nights14nights a year at 32 °F or less

Growing degree days7,412base 50 °F — the season’s usable heat

Longest day14 h 02 mindaylight on June 21

Shortest day10 h 16 mindaylight on December 21

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

Precipitation31.6 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: San Antonio Kelly AFB, TX (2 mi away); precipitation: San Antonio/Seaworld, TX (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

782279a

San Antonio, TX · 1 mi

782439a

San Antonio, TX · 2 mi

782429a

San Antonio, TX · 3 mi

782269a

San Antonio, TX · 3 mi

782379a

San Antonio, TX · 4 mi

782119a

San Antonio, TX · 4 mi

782529a

San Antonio, TX · 5 mi

782259a

San Antonio, TX · 6 mi

Texas planting zones →

Questions about 78236

What planting zone is ZIP code 78236?

ZIP code 78236 (Jbsa Lackland, TX) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Jbsa Lackland, TX?

The median last spring frost (32 °F) near 78236 is February 22; after March 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, San Antonio Kelly AFB station.

When is the first frost in Jbsa Lackland, TX?

The median first fall frost near 78236 is December 2, giving a median frost-free growing season of 284 days.

When should I plant tomatoes in 78236?

Start tomato seeds indoors around Dec 28 – Jan 11 and set transplants outside around Mar 1 – Mar 15, one to three weeks after the median last frost.

How much rain and snow does 78236 get?

About 31.6 inches of precipitation a year (NOAA 1991–2020 normals, San Antonio/Seaworld station).

How hot do summers get in Jbsa Lackland, TX?

The average high peaks at 97 °F in August, with about 141 days a year at 90 °F or more.

What kind of soil does 78236 have?

The USDA soil survey maps Houston Black at the center of ZIP 78236: gravelly clay, moderately well drained, pH about 7.9 (alkaline).

Did spring come early in Jbsa Lackland, TX in 2026?

Spring leaf-out near 78236 came on Jan 20 in 2026, 4 days earlier than the 1991–2020 average (Jan 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Jbsa Lackland, TX?

Short-day onions: the longest day near 78236 is 14 h 02 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.