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

Planting zone for 78070 — Spring Branch, TX

ZIP code 78070 (Spring Branch, Comal County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 1 and the first fall frost December 1.

Where ZIP 78070 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 1
First frostDec 1
2012 zone8b

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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Spring Branch, 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 Spring Branch, TX

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 1median — 50% chance of a later frost
Safe for tender plantsMarch 22only 10% chance of frost after
First fall frostDecember 1median — 10% chance by Nov 9
Growing season276 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 10 and returns around December 19.

From the NOAA station Canyon Dam, TX — 13 miles away, elevation 1,001 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 78070

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 18 – Feb 1
SpinachSow outdoors · Jan 18 – Feb 8
Broccoli, cabbageStart indoors · Dec 21 – Jan 4
Broccoli, cabbageTransplant · Feb 8 – Feb 22
Onion setsPlant outdoors · Feb 1 – Feb 15
PotatoesPlant outdoors · Feb 8 – Feb 22
LettuceSow outdoors · Feb 1 – Feb 15
Carrots, beetsSow outdoors · Feb 8 – Feb 22
TomatoesStart indoors · Jan 4 – Jan 18
TomatoesTransplant · Mar 8 – Mar 22
Peppers, eggplantStart indoors · Dec 21 – Jan 4
Peppers, eggplantTransplant · Mar 15 – Mar 29
BeansSow outdoors · Mar 8 – Mar 22
Sweet cornSow outdoors · Mar 8 – Mar 22
Cucumbers, squashSow outdoors · Mar 8 – Mar 22
Fall lettuce, spinachSow outdoors · Oct 6 – Oct 20
GarlicPlant cloves · Nov 17 – Dec 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 1) and first fall frost (Dec 1) 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 78070 came on Jan 30 — about the same time as the 1991–2020 average (Jan 28).

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 Spring Branch, TX

The soil mapped at the center of ZIP 78070 is Anhalt — clay, well drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH7.3neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter4%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Anhalt clay, 0 to 2 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 78070; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Spring Branch, TX

Summer high96 °Faverage high, August
Winter low40 °Faverage low, January
Hot days103days a year at 90 °F or more
Freezing nights18nights a year at 32 °F or less
Growing degree days6,930base 50 °F — the season’s usable heat
Longest day14 h 04 mindaylight on June 21
Shortest day10 h 13 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation33.8 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 61 °F, low 40 °F 61°40° JanFebruary: average high 65 °F, low 43 °F 65°43° FebMarch: average high 72 °F, low 50 °F 72°50° MarApril: average high 79 °F, low 57 °F 79°57° AprMay: average high 85 °F, low 65 °F 85°65° MayJune: average high 91 °F, low 71 °F 91°71° JunJuly: average high 94 °F, low 73 °F 94°73° JulAugust: average high 96 °F, low 73 °F 96°73° AugSeptember: average high 89 °F, low 68 °F 89°68° SepOctober: average high 81 °F, low 59 °F 81°59° OctNovember: average high 70 °F, low 49 °F 70°49° NovDecember: average high 63 °F, low 42 °F 63°42° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.09 in precipitation 2.1 JanFebruary: 1.91 in precipitation 1.9 FebMarch: 2.53 in precipitation 2.5 MarApril: 2.15 in precipitation 2.1 AprMay: 4.65 in precipitation 4.7 MayJune: 3.51 in precipitation 3.5 JunJuly: 2.20 in precipitation 2.2 JulAugust: 2.10 in precipitation 2.1 AugSeptember: 3.52 in precipitation 3.5 SepOctober: 4.27 in precipitation 4.3 OctNovember: 2.80 in precipitation 2.8 NovDecember: 2.06 in precipitation, 0.1 in snowfall 2.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Canyon Dam, TX (13 mi away); precipitation: Spring Branch 2se, TX (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

780048b
Bergheim, TX · 8 mi
781638b
Bulverde, TX · 9 mi
781339a
Canyon Lake, TX · 9 mi
780278b
Kendalia, TX · 9 mi
786239a
Fischer, TX · 12 mi
786068b
Blanco, TX · 14 mi
782619a
San Antonio, TX · 14 mi
782608b
San Antonio, TX · 14 mi

Texas planting zones →

Questions about 78070

What planting zone is ZIP code 78070?

ZIP code 78070 (Spring Branch, 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 Spring Branch, TX?

The median last spring frost (32 °F) near 78070 is March 1; after March 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Canyon Dam station.

When is the first frost in Spring Branch, TX?

The median first fall frost near 78070 is December 1, giving a median frost-free growing season of 276 days.

When should I plant tomatoes in 78070?

Start tomato seeds indoors around Jan 4 – Jan 18 and set transplants outside around Mar 8 – Mar 22, one to three weeks after the median last frost.

How much rain and snow does 78070 get?

About 33.8 inches of precipitation a year (NOAA 1991–2020 normals, Spring Branch 2se station).

How hot do summers get in Spring Branch, TX?

The average high peaks at 96 °F in August, with about 103 days a year at 90 °F or more.

What kind of soil does 78070 have?

The USDA soil survey maps Anhalt at the center of ZIP 78070: clay, well drained, pH about 7.3 (neutral).

Did spring come early in Spring Branch, TX in 2026?

Spring leaf-out near 78070 came on Jan 30 in 2026, about the same as the 1991–2020 average (Jan 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Spring Branch, TX?

Short-day onions: the longest day near 78070 is 14 h 04 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.