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

Planting zone for 79506 — Blackwell, TX

ZIP code 79506 (Blackwell, Nolan 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 4.

Where ZIP 79506 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 4
2012 zone8a

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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Blackwell, 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 Blackwell, 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 4median — 10% chance by Oct 23
Growing season222 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 14 and returns around November 12.

From the NOAA station Bronte 11 Nne, TX — 7 miles away, elevation 1,998 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 79506

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 9 – Sep 23
GarlicPlant cloves · Oct 21 – Nov 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 28) and first fall frost (Nov 4) 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 79506 came on Feb 8 — about the same time as the 1991–2020 average (Feb 8).

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 Blackwell, TX

The soil mapped at the center of ZIP 79506 is Sagerton — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.4%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Sagerton clay loam, 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 79506; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Blackwell, TX

Summer high95 °Faverage high, July
Winter low29 °Faverage low, January
Hot days106days a year at 90 °F or more
Freezing nights73nights a year at 32 °F or less
Growing degree days5,722base 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
Precipitation22.8 inper year, rain and melted snow
Snowfall1 inper year

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 59 °F, low 29 °F 59°29° JanFebruary: average high 63 °F, low 34 °F 63°34° FebMarch: average high 71 °F, low 42 °F 71°42° MarApril: average high 79 °F, low 51 °F 79°51° AprMay: average high 86 °F, low 59 °F 86°59° MayJune: average high 92 °F, low 67 °F 92°67° JunJuly: average high 95 °F, low 68 °F 95°68° JulAugust: average high 94 °F, low 69 °F 94°69° AugSeptember: average high 88 °F, low 62 °F 88°62° SepOctober: average high 78 °F, low 50 °F 78°50° OctNovember: average high 67 °F, low 38 °F 67°38° NovDecember: average high 59 °F, low 31 °F 59°31° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.89 in precipitation 0.9 JanFebruary: 1.08 in precipitation, 0.1 in snowfall 1.1 FebMarch: 1.53 in precipitation 1.5 MarApril: 1.68 in precipitation, 0.2 in snowfall 1.7 AprMay: 3.29 in precipitation 3.3 MayJune: 2.77 in precipitation 2.8 JunJuly: 1.71 in precipitation 1.7 JulAugust: 2.86 in precipitation 2.9 AugSeptember: 2.46 in precipitation 2.5 SepOctober: 2.27 in precipitation 2.3 OctNovember: 1.36 in precipitation, 0.2 in snowfall 1.4 NovDecember: 0.93 in precipitation 0.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bronte 11 Nne, TX (7 mi away); precipitation: Oak Creek Lake, TX (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

795358a
Maryneal, TX · 11 mi
795378a
Nolan, TX · 13 mi
795668a
Wingate, TX · 13 mi
769338a
Bronte, TX · 17 mi
768658a
Norton, TX · 21 mi
769458a
Robert Lee, TX · 23 mi
795458a
Roscoe, TX · 25 mi
795568a
Sweetwater, TX · 26 mi

Texas planting zones →

Questions about 79506

What planting zone is ZIP code 79506?

ZIP code 79506 (Blackwell, 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 Blackwell, TX?

The median last spring frost (32 °F) near 79506 is March 28; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bronte 11 Nne station.

When is the first frost in Blackwell, TX?

The median first fall frost near 79506 is November 4, giving a median frost-free growing season of 222 days.

When should I plant tomatoes in 79506?

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 79506 get?

About 22.8 inches of precipitation a year and 1 inches of snowfall (NOAA 1991–2020 normals, Oak Creek Lake station).

How hot do summers get in Blackwell, TX?

The average high peaks at 95 °F in July, with about 106 days a year at 90 °F or more.

What kind of soil does 79506 have?

The USDA soil survey maps Sagerton at the center of ZIP 79506: clay loam, well drained, pH about 7.2 (neutral).

Did spring come early in Blackwell, TX in 2026?

Spring leaf-out near 79506 came on Feb 8 in 2026, about the same as the 1991–2020 average (Feb 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Blackwell, TX?

Short-day onions: the longest day near 79506 is 14 h 15 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.