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

Planting zone for 78069 — Somerset, TX

ZIP code 78069 (Somerset, Bexar County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 24 and the first fall frost December 2.

Where ZIP 78069 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 24

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 Somerset, 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 Somerset, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostFebruary 24median — 50% chance of a later frost

Safe for tender plantsMarch 14only 10% chance of frost after

First fall frostDecember 2median — 10% chance by Nov 14

Growing season283 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 4 and returns around December 18.

From the NOAA station Lytle 3w, TX — 11 miles away, elevation 722 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 78069

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 13 – Jan 27

SpinachSow outdoors · Jan 13 – Feb 3

Broccoli, cabbageStart indoors · Dec 16 – Dec 30

Broccoli, cabbageTransplant · Feb 3 – Feb 17

Onion setsPlant outdoors · Jan 27 – Feb 10

PotatoesPlant outdoors · Feb 3 – Feb 17

LettuceSow outdoors · Jan 27 – Feb 10

Carrots, beetsSow outdoors · Feb 3 – Feb 17

TomatoesStart indoors · Dec 30 – Jan 13

TomatoesTransplant · Mar 3 – Mar 17

Peppers, eggplantStart indoors · Dec 16 – Dec 30

Peppers, eggplantTransplant · Mar 10 – Mar 24

BeansSow outdoors · Mar 3 – Mar 17

Sweet cornSow outdoors · Mar 3 – Mar 17

Cucumbers, squashSow outdoors · Mar 3 – Mar 17

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 24) 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 78069 came on Jan 15 — 9 days earlier than the 1991–2020 average (Jan 24).

average
Jan 242026
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 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 Somerset, TX.

Soil in Somerset, TX

The soil mapped at the center of ZIP 78069 is Poth — loamy fine sand, well drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding

pH6.5neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Poth loamy fine sand, 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 78069; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Somerset, TX

Summer high96 °Faverage high, July

Winter low42 °Faverage low, January

Hot days120days a year at 90 °F or more

Freezing nights17nights a year at 32 °F or less

Growing degree days7,659base 50 °F — the season’s usable heat

Longest day14 h 01 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

Precipitation29.4 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: Lytle 3w, TX (11 mi away); precipitation: Poteet 4.9 W, TX (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

San Antonio, TX · 10 mi

780599a

Natalia, TX · 10 mi

782529a

San Antonio, TX · 10 mi

Texas planting zones →

Questions about 78069

What planting zone is ZIP code 78069?

ZIP code 78069 (Somerset, 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 Somerset, TX?

The median last spring frost (32 °F) near 78069 is February 24; after March 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lytle 3w station.

When is the first frost in Somerset, TX?

The median first fall frost near 78069 is December 2, giving a median frost-free growing season of 283 days.

When should I plant tomatoes in 78069?

Start tomato seeds indoors around Dec 30 – Jan 13 and set transplants outside around Mar 3 – Mar 17, one to three weeks after the median last frost.

How much rain and snow does 78069 get?

About 29.4 inches of precipitation a year (NOAA 1991–2020 normals, Poteet 4.9 W station).

How hot do summers get in Somerset, TX?

The average high peaks at 96 °F in July, with about 120 days a year at 90 °F or more.

What kind of soil does 78069 have?

The USDA soil survey maps Poth at the center of ZIP 78069: loamy fine sand, well drained, pH about 6.5 (neutral).

Did spring come early in Somerset, TX in 2026?

Spring leaf-out near 78069 came on Jan 15 in 2026, 9 days earlier than the 1991–2020 average (Jan 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Somerset, TX?

Short-day onions: the longest day near 78069 is 14 h 01 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.