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

Planting zone for 79539 — O Brien, TX

ZIP code 79539 (O Brien, Haskell County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 28 and the first fall frost November 7.

Where ZIP 79539 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostMar 28
First frostNov 7
2012 zone7b

Was 7b 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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for O Brien, 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 O Brien, TX

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 28median — 50% chance of a later frost
Safe for tender plantsApril 14only 10% chance of frost after
First fall frostNovember 7median — 10% chance by Oct 25
Growing season225 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 17.

From the NOAA station Haskell, TX — 16 miles away, elevation 1,591 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 79539

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 14 – Feb 28
SpinachSow outdoors · Feb 14 – Mar 7
Broccoli, cabbageStart indoors · Jan 17 – Jan 31
Broccoli, cabbageTransplant · Mar 7 – Mar 21
Onion setsPlant outdoors · Feb 28 – Mar 14
PotatoesPlant outdoors · Mar 7 – Mar 21
LettuceSow outdoors · Feb 28 – Mar 14
Carrots, beetsSow outdoors · Mar 7 – Mar 21
TomatoesStart indoors · Jan 31 – Feb 14
TomatoesTransplant · Apr 4 – Apr 18
Peppers, eggplantStart indoors · Jan 17 – Jan 31
Peppers, eggplantTransplant · Apr 11 – Apr 25
BeansSow outdoors · Apr 4 – Apr 18
Sweet cornSow outdoors · Apr 4 – Apr 18
Cucumbers, squashSow outdoors · Apr 4 – Apr 18
Fall lettuce, spinachSow outdoors · Sep 12 – Sep 26
GarlicPlant cloves · Oct 24 – Nov 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 28) and first fall frost (Nov 7) 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 79539 came on Feb 9 — about the same time as the 1991–2020 average (Feb 9).

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).

Soil in O Brien, TX

The soil mapped at the center of ZIP 79539 is Devol — loamy sand, well drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Devol-Nobscot complex, 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 79539; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in O Brien, TX

Summer high95 °Faverage high, July
Winter low29 °Faverage low, January
Hot days110days a year at 90 °F or more
Freezing nights63nights a year at 32 °F or less
Growing degree days5,711base 50 °F — the season’s usable heat
Longest day14 h 22 mindaylight on June 21
Shortest day9 h 56 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation26.4 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 56 °F, low 29 °F 56°29° JanFebruary: average high 59 °F, low 32 °F 59°32° FebMarch: average high 68 °F, low 40 °F 68°40° MarApril: average high 77 °F, low 49 °F 77°49° AprMay: average high 85 °F, low 59 °F 85°59° MayJune: average high 92 °F, low 68 °F 92°68° JunJuly: average high 95 °F, low 72 °F 95°72° JulAugust: average high 95 °F, low 71 °F 95°71° AugSeptember: average high 87 °F, low 63 °F 87°63° SepOctober: average high 77 °F, low 51 °F 77°51° OctNovember: average high 65 °F, low 40 °F 65°40° NovDecember: average high 56 °F, low 31 °F 56°31° Dec

Precipitation by month inches

0″1″2″3″4″January: 1.20 in precipitation 1.2 JanFebruary: 1.52 in precipitation 1.5 FebMarch: 1.44 in precipitation 1.4 MarApril: 2.04 in precipitation 2.0 AprMay: 3.33 in precipitation 3.3 MayJune: 3.85 in precipitation 3.9 JunJuly: 1.97 in precipitation 2.0 JulAugust: 2.59 in precipitation 2.6 AugSeptember: 3.32 in precipitation 3.3 SepOctober: 2.35 in precipitation 2.4 OctNovember: 1.61 in precipitation 1.6 NovDecember: 1.14 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Haskell, TX (16 mi away); precipitation: Rule 0.5 Nw, TX (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

795448a
Rochester, TX · 5 mi
795298a
Knox City, TX · 6 mi
795478a
Rule, TX · 11 mi
795058a
Benjamin, TX · 14 mi
763888a
Weinert, TX · 14 mi
763718a
Munday, TX · 16 mi
795408a
Old Glory, TX · 18 mi
795488a
Rule, TX · 20 mi

Texas planting zones →

Questions about 79539

What planting zone is ZIP code 79539?

ZIP code 79539 (O Brien, TX) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in O Brien, TX?

The median last spring frost (32 °F) near 79539 is March 28; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Haskell station.

When is the first frost in O Brien, TX?

The median first fall frost near 79539 is November 7, giving a median frost-free growing season of 225 days.

When should I plant tomatoes in 79539?

Start tomato seeds indoors around Jan 31 – Feb 14 and set transplants outside around Apr 4 – Apr 18, one to three weeks after the median last frost.

How much rain and snow does 79539 get?

About 26.4 inches of precipitation a year (NOAA 1991–2020 normals, Rule 0.5 Nw station).

How hot do summers get in O Brien, TX?

The average high peaks at 95 °F in July, with about 110 days a year at 90 °F or more.

What kind of soil does 79539 have?

The USDA soil survey maps Devol at the center of ZIP 79539: loamy sand, well drained, pH about 6.7 (neutral).

Did spring come early in O Brien, TX in 2026?

Spring leaf-out near 79539 came on Feb 9 in 2026, about the same as the 1991–2020 average (Feb 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in O Brien, TX?

Intermediate onions: the longest day near 79539 is 14 h 22 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 79539 change?

Yes. The 2012 USDA map put 79539 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.