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

Planting zone for 76631 — Bynum, TX

ZIP code 76631 (Bynum, Hill County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 21 and the first fall frost November 10.

Where ZIP 76631 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostMar 21

First frostNov 10

2012 zone8a

Was 8a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bynum, 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 Bynum, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 21median — 50% chance of a later frost

Safe for tender plantsApril 8only 10% chance of frost after

First fall frostNovember 10median — 10% chance by Oct 28

Growing season235 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 9 and returns around November 22.

From the NOAA station Hillsboro, TX — 9 miles away, elevation 551 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 76631

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 7 – Feb 21

SpinachSow outdoors · Feb 7 – Feb 28

Broccoli, cabbageStart indoors · Jan 10 – Jan 24

Broccoli, cabbageTransplant · Feb 28 – Mar 14

Onion setsPlant outdoors · Feb 21 – Mar 7

PotatoesPlant outdoors · Feb 28 – Mar 14

LettuceSow outdoors · Feb 21 – Mar 7

Carrots, beetsSow outdoors · Feb 28 – Mar 14

TomatoesStart indoors · Jan 24 – Feb 7

TomatoesTransplant · Mar 28 – Apr 11

Peppers, eggplantStart indoors · Jan 10 – Jan 24

Peppers, eggplantTransplant · Apr 4 – Apr 18

BeansSow outdoors · Mar 28 – Apr 11

Sweet cornSow outdoors · Mar 28 – Apr 11

Cucumbers, squashSow outdoors · Mar 28 – Apr 11

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 21) and first fall frost (Nov 10) 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 76631 came on Feb 7 — 4 days later than the 1991–2020 average (Feb 3).

average
Feb 32026
Feb 7

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 8b in Texas

620 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 Bynum, TX.

Soil in Bynum, TX

The soil mapped at the center of ZIP 76631 is Houston Black — clay, moderately well drained.

TextureClayholds 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 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 76631; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bynum, TX

Summer high97 °Faverage high, August

Winter low34 °Faverage low, January

Hot days105days a year at 90 °F or more

Freezing nights37nights a year at 32 °F or less

Growing degree days6,434base 50 °F — the season’s usable heat

Longest day14 h 15 mindaylight on June 21

Shortest day10 h 03 mindaylight on December 21

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

Precipitation39.3 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: Hillsboro, TX (9 mi away); precipitation: Brandon, TX (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

Hillsboro, TX · 10 mi

Texas planting zones →

Questions about 76631

What planting zone is ZIP code 76631?

ZIP code 76631 (Bynum, TX) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Bynum, TX?

The median last spring frost (32 °F) near 76631 is March 21; after April 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hillsboro station.

When is the first frost in Bynum, TX?

The median first fall frost near 76631 is November 10, giving a median frost-free growing season of 235 days.

When should I plant tomatoes in 76631?

Start tomato seeds indoors around Jan 24 – Feb 7 and set transplants outside around Mar 28 – Apr 11, one to three weeks after the median last frost.

How much rain and snow does 76631 get?

About 39.3 inches of precipitation a year (NOAA 1991–2020 normals, Brandon station).

How hot do summers get in Bynum, TX?

The average high peaks at 97 °F in August, with about 105 days a year at 90 °F or more.

What kind of soil does 76631 have?

The USDA soil survey maps Houston Black at the center of ZIP 76631: clay, moderately well drained, pH about 7.9 (alkaline).

Did spring come early in Bynum, TX in 2026?

Spring leaf-out near 76631 came on Feb 7 in 2026, 4 days later than the 1991–2020 average (Feb 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bynum, TX?

Short-day onions: the longest day near 76631 is 14 h 15 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 76631 change?

Yes. The 2012 USDA map put 76631 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.