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

Planting zone for 78643 — Llano, TX

ZIP code 78643 (Llano, Llano County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 20 and the first fall frost November 10.

Where ZIP 78643 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 20

First frostNov 10

2012 zone8a

Was 8a 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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Llano, 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 Llano, TX

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

Safe for tender plantsApril 11only 10% chance of frost after

First fall frostNovember 10median — 10% chance by Oct 28

Growing season235 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 5 and returns around November 21.

From the NOAA station Llano, TX — 6 miles away, elevation 1,020 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 78643

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 6 – Feb 20

SpinachSow outdoors · Feb 6 – Feb 27

Broccoli, cabbageStart indoors · Jan 9 – Jan 23

Broccoli, cabbageTransplant · Feb 27 – Mar 13

Onion setsPlant outdoors · Feb 20 – Mar 6

PotatoesPlant outdoors · Feb 27 – Mar 13

LettuceSow outdoors · Feb 20 – Mar 6

Carrots, beetsSow outdoors · Feb 27 – Mar 13

TomatoesStart indoors · Jan 23 – Feb 6

TomatoesTransplant · Mar 27 – Apr 10

Peppers, eggplantStart indoors · Jan 9 – Jan 23

Peppers, eggplantTransplant · Apr 3 – Apr 17

BeansSow outdoors · Mar 27 – Apr 10

Sweet cornSow outdoors · Mar 27 – Apr 10

Cucumbers, squashSow outdoors · Mar 27 – Apr 10

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 20) and first fall frost (Nov 10) 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 78643 came on Jan 30 — about the same time as the 1991–2020 average (Jan 31).

average
Jan 312026
Jan 30

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 8b in Texas

620 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 Llano, TX.

Soil in Llano, TX

The soil mapped at the center of ZIP 78643 is Ligon — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Ligon fine sandy loam, 1 to 5 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 78643; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Llano, TX

Summer high97 °Faverage high, August

Winter low34 °Faverage low, January

Hot days120days a year at 90 °F or more

Freezing nights50nights a year at 32 °F or less

Growing degree days6,680base 50 °F — the season’s usable heat

Longest day14 h 08 mindaylight on June 21

Shortest day10 h 09 mindaylight on December 21

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

Precipitation29.7 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: Llano, TX (6 mi away); precipitation: Llano 0.5 Ese, TX (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

768858b

Valley Spring, TX · 15 mi

768318b

Castell, TX · 15 mi

786398b

Kingsland, TX · 16 mi

786098b

Buchanan Dam, TX · 16 mi

786078b

Bluffton, TX · 17 mi

786758b

Willow City, TX · 17 mi

Texas planting zones →

Questions about 78643

What planting zone is ZIP code 78643?

ZIP code 78643 (Llano, 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 Llano, TX?

The median last spring frost (32 °F) near 78643 is March 20; after April 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Llano station.

When is the first frost in Llano, TX?

The median first fall frost near 78643 is November 10, giving a median frost-free growing season of 235 days.

When should I plant tomatoes in 78643?

Start tomato seeds indoors around Jan 23 – Feb 6 and set transplants outside around Mar 27 – Apr 10, one to three weeks after the median last frost.

How much rain and snow does 78643 get?

About 29.7 inches of precipitation a year (NOAA 1991–2020 normals, Llano 0.5 Ese station).

How hot do summers get in Llano, TX?

The average high peaks at 97 °F in August, with about 120 days a year at 90 °F or more.

What kind of soil does 78643 have?

The USDA soil survey maps Ligon at the center of ZIP 78643: fine sandy loam, well drained, pH about 6.7 (neutral).

Did spring come early in Llano, TX in 2026?

Spring leaf-out near 78643 came on Jan 30 in 2026, about the same as the 1991–2020 average (Jan 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Llano, TX?

Short-day onions: the longest day near 78643 is 14 h 08 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 78643 change?

Yes. The 2012 USDA map put 78643 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.