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

Planting zone for 77456 — Markham, TX

ZIP code 77456 (Markham, Matagorda County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 20 and the first fall frost December 3.

Where ZIP 77456 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.

Zone9b25 to 30 °F

Coldest night−3.9 to −1.1 °C

Last frostFeb 20

First frostDec 3

2012 zone9a

Was 9a 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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Markham, 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 Markham, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostFebruary 20median — 50% chance of a later frost

Safe for tender plantsMarch 15only 10% chance of frost after

First fall frostDecember 3median — 10% chance by Nov 10

Growing season290 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 31 and returns around December 22.

From the NOAA station Bay City Wtr Wks, TX — 8 miles away, elevation 52 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 77456

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 9 – Jan 23

SpinachSow outdoors · Jan 9 – Jan 30

Broccoli, cabbageStart indoors · Dec 12 – Dec 26

Broccoli, cabbageTransplant · Jan 30 – Feb 13

Onion setsPlant outdoors · Jan 23 – Feb 6

PotatoesPlant outdoors · Jan 30 – Feb 13

LettuceSow outdoors · Jan 23 – Feb 6

Carrots, beetsSow outdoors · Jan 30 – Feb 13

TomatoesStart indoors · Dec 26 – Jan 9

TomatoesTransplant · Feb 27 – Mar 13

Peppers, eggplantStart indoors · Dec 12 – Dec 26

Peppers, eggplantTransplant · Mar 6 – Mar 20

BeansSow outdoors · Feb 27 – Mar 13

Sweet cornSow outdoors · Feb 27 – Mar 13

Cucumbers, squashSow outdoors · Feb 27 – Mar 13

Fall lettuce, spinachSow outdoors · Oct 8 – Oct 22

GarlicPlant cloves · Nov 19 – Dec 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 20) and first fall frost (Dec 3) 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 77456 came on Jan 15 — 8 days earlier than the 1991–2020 average (Jan 23).

average
Jan 232026
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 9b in Texas

646 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 25 °F or colder — the bottom of zone 9b. 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 Markham, TX.

Soil in Markham, TX

The soil mapped at the center of ZIP 77456 is Laewest — clay, moderately well drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH6.3slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter4%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classprime farmlandUSDA classification

Map unit: Laewest 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 77456; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Markham, TX

Summer high91 °Faverage high, July

Winter low43 °Faverage low, January

Hot days88days a year at 90 °F or more

Freezing nights7nights a year at 32 °F or less

Growing degree days7,078base 50 °F — the season’s usable heat

Longest day13 h 59 mindaylight on June 21

Shortest day10 h 18 mindaylight on December 21

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

Precipitation49.1 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: Bay City Wtr Wks, TX (8 mi away); precipitation: Bay City Wtr Wks, TX (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

Van Vleck, TX · 16 mi

774839b

Wadsworth, TX · 17 mi

Texas planting zones →

Questions about 77456

What planting zone is ZIP code 77456?

ZIP code 77456 (Markham, TX) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in Markham, TX?

The median last spring frost (32 °F) near 77456 is February 20; after March 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bay City Wtr Wks station.

When is the first frost in Markham, TX?

The median first fall frost near 77456 is December 3, giving a median frost-free growing season of 290 days.

When should I plant tomatoes in 77456?

Start tomato seeds indoors around Dec 26 – Jan 9 and set transplants outside around Feb 27 – Mar 13, one to three weeks after the median last frost.

How much rain and snow does 77456 get?

About 49.1 inches of precipitation a year (NOAA 1991–2020 normals, Bay City Wtr Wks station).

How hot do summers get in Markham, TX?

The average high peaks at 91 °F in July, with about 88 days a year at 90 °F or more.

What kind of soil does 77456 have?

The USDA soil survey maps Laewest at the center of ZIP 77456: clay, moderately well drained, pH about 6.3 (slightly acidic).

Did spring come early in Markham, TX in 2026?

Spring leaf-out near 77456 came on Jan 15 in 2026, 8 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Markham, TX?

Short-day onions: the longest day near 77456 is 13 h 59 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 77456 change?

Yes. The 2012 USDA map put 77456 in zone 9a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.