Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for Seguin, TX

Seguin, TX is in USDA zone 9a across its 2 ZIP codes. The median last spring frost is March 1 and the first fall frost November 26.

Seguin on the zone map

Outlined: its 1 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.

Zone9a20 to 25 °F

ZIP codes2

Last frostMar 1

First frostNov 26

Growing season273 days

9a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Seguin, 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 Seguin, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 1median — 50% chance of a later frost

Safe for tender plantsMarch 20only 10% chance of frost after

First fall frostNovember 26median — 10% chance by Nov 8

Growing season273 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 13 and returns around December 11.

From the NOAA station Austin San Antonio, TX, elevation 633 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 Seguin

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 18 – Feb 1

SpinachSow outdoors · Jan 18 – Feb 8

Broccoli, cabbageStart indoors · Dec 21 – Jan 4

Broccoli, cabbageTransplant · Feb 8 – Feb 22

Onion setsPlant outdoors · Feb 1 – Feb 15

PotatoesPlant outdoors · Feb 8 – Feb 22

LettuceSow outdoors · Feb 1 – Feb 15

Carrots, beetsSow outdoors · Feb 8 – Feb 22

TomatoesStart indoors · Jan 4 – Jan 18

TomatoesTransplant · Mar 8 – Mar 22

Peppers, eggplantStart indoors · Dec 21 – Jan 4

Peppers, eggplantTransplant · Mar 15 – Mar 29

BeansSow outdoors · Mar 8 – Mar 22

Sweet cornSow outdoors · Mar 8 – Mar 22

Cucumbers, squashSow outdoors · Mar 8 – Mar 22

Fall lettuce, spinachSow outdoors · Oct 1 – Oct 15

GarlicPlant cloves · Nov 12 – Dec 17

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 1) and first fall frost (Nov 26) 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 78156 came on Jan 20 — 5 days earlier than the 1991–2020 average (Jan 25).

average
Jan 252026
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 Seguin, TX.

Soil in Seguin, TX

The soil mapped at the center of ZIP 78156 is Branyon — clay, moderately well drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH7.8slightly alkaline; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classprime farmlandUSDA classification

Map unit: Branyon clay, 0 to 1 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 78156; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Seguin, TX

Summer high98 °Faverage high, August

Winter low40 °Faverage low, January

Hot days128days a year at 90 °F or more

Freezing nights20nights a year at 32 °F or less

Growing degree days7,389base 50 °F — the season’s usable heat

Longest day14 h 03 mindaylight on June 21

Shortest day10 h 15 mindaylight on December 21

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

Precipitation35.8 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: Austin San Antonio, TX (7 mi away); precipitation: Mcqueeney 0.5 Ene, TX (4 mi away). Daylight is calculated from latitude.

ZIP codes in Seguin

Texas planting zones →

Questions about Seguin

What planting zone is Seguin, TX?

Seguin, TX is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Seguin, TX?

The median last spring frost is March 1 and the median first fall frost is November 26 (NOAA 1991–2020 normals, Austin San Antonio station).

When can I plant a garden in Seguin, TX?

Cool-season crops like peas and spinach go in around Jan 18 – Feb 8; tomatoes, peppers, beans and squash after about Mar 8, once frost risk has passed.

What kind of onions grow in Seguin, TX?

Short-day onions: the longest day is 14 h 03 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

How much rain and snow does Seguin, TX get?

About 35.8 inches of precipitation a year (NOAA 1991–2020 normals).