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

Planting zone for 78842 — Del Rio, TX

ZIP code 78842 (Del Rio, Val Verde County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 14 and the first fall frost December 6.

Where ZIP 78842 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostFeb 14
First frostDec 6
2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Del Rio, 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 Del Rio, TX

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 14median — 50% chance of a later frost
Safe for tender plantsMarch 9only 10% chance of frost after
First fall frostDecember 6median — 10% chance by Nov 16
Growing season297 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 26 and returns around December 22.

From the NOAA station Amistad Dam, TX — 12 miles away, elevation 1,158 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 78842

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 3 – Jan 17
SpinachSow outdoors · Jan 3 – Jan 24
Broccoli, cabbageStart indoors · Dec 6 – Dec 20
Broccoli, cabbageTransplant · Jan 24 – Feb 7
Onion setsPlant outdoors · Jan 17 – Jan 31
PotatoesPlant outdoors · Jan 24 – Feb 7
LettuceSow outdoors · Jan 17 – Jan 31
Carrots, beetsSow outdoors · Jan 24 – Feb 7
TomatoesStart indoors · Dec 20 – Jan 3
TomatoesTransplant · Feb 21 – Mar 7
Peppers, eggplantStart indoors · Dec 6 – Dec 20
Peppers, eggplantTransplant · Feb 28 – Mar 14
BeansSow outdoors · Feb 21 – Mar 7
Sweet cornSow outdoors · Feb 21 – Mar 7
Cucumbers, squashSow outdoors · Feb 21 – Mar 7
Fall lettuce, spinachSow outdoors · Oct 11 – Oct 25
GarlicPlant cloves · Nov 22 – Dec 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 14) and first fall frost (Dec 6) 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 78842 came on Feb 1 — 5 days later than the 1991–2020 average (Jan 27).

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.

Trees 72

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °FArizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °F

Shrubs 141

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Faloe yucca15 ft · blooms early summer · medium shade tolerance · to −1 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °FAmerican snowbell10 ft · blooms spring · medium shade tolerance · to −16 °F

Wildflowers & perennials 208

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican century plant6 ft · blooms indeterminate · high shade tolerance · to 12 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 196

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °FArizona fescue2 ft · blooms late spring · high shade tolerance · to −23 °FArizona threeawn2 ft · blooms mid summer · high shade tolerance · to −3 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °F

Vines 14

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °F

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 Del Rio, TX.

Soil in Del Rio, TX

The soil mapped at the center of ZIP 78842 is Zorra — very stony loam, well drained.

TextureVery stony loama good balance for most vegetables
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Zorra-Rock outcrop complex, 8 to 15 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 78842; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Del Rio, TX

Summer high97 °Faverage high, July
Winter low40 °Faverage low, January
Hot days138days a year at 90 °F or more
Freezing nights12nights a year at 32 °F or less
Growing degree days7,369base 50 °F — the season’s usable heat
Longest day14 h 03 mindaylight on June 21
Shortest day10 h 14 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation19.4 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 63 °F, low 40 °F 63°40° JanFebruary: average high 68 °F, low 43 °F 68°43° FebMarch: average high 76 °F, low 51 °F 76°51° MarApril: average high 83 °F, low 58 °F 83°58° AprMay: average high 89 °F, low 66 °F 89°66° MayJune: average high 95 °F, low 72 °F 95°72° JunJuly: average high 97 °F, low 74 °F 97°74° JulAugust: average high 97 °F, low 74 °F 97°74° AugSeptember: average high 90 °F, low 69 °F 90°69° SepOctober: average high 82 °F, low 60 °F 82°60° OctNovember: average high 71 °F, low 49 °F 71°49° NovDecember: average high 63 °F, low 41 °F 63°41° Dec

Precipitation by month inches

0″1″2″3″4″January: 0.67 in precipitation, 0.1 in snowfall 0.7 JanFebruary: 0.66 in precipitation 0.7 FebMarch: 1.45 in precipitation 1.4 MarApril: 1.27 in precipitation 1.3 AprMay: 2.61 in precipitation 2.6 MayJune: 1.83 in precipitation 1.8 JunJuly: 1.85 in precipitation 1.9 JulAugust: 2.50 in precipitation 2.5 AugSeptember: 3.18 in precipitation 3.2 SepOctober: 1.68 in precipitation 1.7 OctNovember: 1.04 in precipitation 1.0 NovDecember: 0.69 in precipitation 0.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Amistad Dam, TX (12 mi away); precipitation: Amistad Dam, TX (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

788408b
Del Rio, TX · 8 mi
788479a
Del Rio, TX · 20 mi
788439a
Laughlin Afb, TX · 24 mi
788378b
Comstock, TX · 26 mi
788418b
Del Rio, TX · 31 mi
788329a
Brackettville, TX · 40 mi
788718b
Langtry, TX · 41 mi
788808b
Rocksprings, TX · 49 mi

All 4 ZIP codes in Del Rio → · Texas planting zones →

Questions about 78842

What planting zone is ZIP code 78842?

ZIP code 78842 (Del Rio, TX) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Del Rio, TX?

The median last spring frost (32 °F) near 78842 is February 14; after March 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Amistad Dam station.

When is the first frost in Del Rio, TX?

The median first fall frost near 78842 is December 6, giving a median frost-free growing season of 297 days.

When should I plant tomatoes in 78842?

Start tomato seeds indoors around Dec 20 – Jan 3 and set transplants outside around Feb 21 – Mar 7, one to three weeks after the median last frost.

How much rain and snow does 78842 get?

About 19.4 inches of precipitation a year (NOAA 1991–2020 normals, Amistad Dam station).

How hot do summers get in Del Rio, TX?

The average high peaks at 97 °F in July, with about 138 days a year at 90 °F or more.

What kind of soil does 78842 have?

The USDA soil survey maps Zorra at the center of ZIP 78842: very stony loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Del Rio, TX in 2026?

Spring leaf-out near 78842 came on Feb 1 in 2026, 5 days later than the 1991–2020 average (Jan 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Del Rio, TX?

Short-day onions: the longest day near 78842 is 14 h 03 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.