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

Planting zone for Conroe, TX

Conroe, TX is in USDA zone 9a across its 8 ZIP codes. The median last spring frost is March 11 and the first fall frost November 19.

Conroe on the zone map

Outlined: its 7 ZIP code areas · 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
ZIP codes8
Last frostMar 11
First frostNov 19
Growing season253 days

9a 8 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Conroe, 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 Conroe, TX

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 11median — 50% chance of a later frost
Safe for tender plantsApril 3only 10% chance of frost after
First fall frostNovember 19median — 10% chance by Nov 1
Growing season253 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 21 and returns around December 4.

From the NOAA station Conroe Montgomery Co. Airport, TX, elevation 246 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 Conroe

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 28 – Feb 11
SpinachSow outdoors · Jan 28 – Feb 18
Broccoli, cabbageStart indoors · Dec 31 – Jan 14
Broccoli, cabbageTransplant · Feb 18 – Mar 4
Onion setsPlant outdoors · Feb 11 – Feb 25
PotatoesPlant outdoors · Feb 18 – Mar 4
LettuceSow outdoors · Feb 11 – Feb 25
Carrots, beetsSow outdoors · Feb 18 – Mar 4
TomatoesStart indoors · Jan 14 – Jan 28
TomatoesTransplant · Mar 18 – Apr 1
Peppers, eggplantStart indoors · Dec 31 – Jan 14
Peppers, eggplantTransplant · Mar 25 – Apr 8
BeansSow outdoors · Mar 18 – Apr 1
Sweet cornSow outdoors · Mar 18 – Apr 1
Cucumbers, squashSow outdoors · Mar 18 – Apr 1
Fall lettuce, spinachSow outdoors · Sep 24 – Oct 8
GarlicPlant cloves · Nov 5 – Dec 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 11) and first fall frost (Nov 19) 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 77305 came on Jan 11 — 14 days earlier than the 1991–2020 average (Jan 25).

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 Conroe, TX.

Soil in Conroe, TX

The soil mapped at the center of ZIP 77305 is Splendora — fine sandy loam, somewhat poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH4.6strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Splendora fine sandy loam, 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 77305; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Conroe, TX

Summer high95 °Faverage high, August
Winter low39 °Faverage low, January
Hot days108days a year at 90 °F or more
Freezing nights27nights a year at 32 °F or less
Growing degree days6,776base 50 °F — the season’s usable heat
Longest day14 h 06 mindaylight on June 21
Shortest day10 h 11 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation47.6 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 62 °F, low 39 °F 62°39° JanFebruary: average high 66 °F, low 43 °F 66°43° FebMarch: average high 73 °F, low 49 °F 73°49° MarApril: average high 79 °F, low 55 °F 79°55° AprMay: average high 86 °F, low 64 °F 86°64° MayJune: average high 91 °F, low 70 °F 91°70° JunJuly: average high 94 °F, low 72 °F 94°72° JulAugust: average high 95 °F, low 72 °F 95°72° AugSeptember: average high 90 °F, low 66 °F 90°66° SepOctober: average high 82 °F, low 56 °F 82°56° OctNovember: average high 71 °F, low 47 °F 71°47° NovDecember: average high 64 °F, low 41 °F 64°41° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 4.25 in precipitation 4.3 JanFebruary: 2.94 in precipitation 2.9 FebMarch: 2.99 in precipitation 3.0 MarApril: 3.10 in precipitation 3.1 AprMay: 4.79 in precipitation 4.8 MayJune: 4.42 in precipitation 4.4 JunJuly: 3.15 in precipitation 3.1 JulAugust: 3.85 in precipitation 3.9 AugSeptember: 3.60 in precipitation 3.6 SepOctober: 5.52 in precipitation 5.5 OctNovember: 5.13 in precipitation 5.1 NovDecember: 3.91 in precipitation 3.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Conroe Montgomery Co. Airport, TX (5 mi away); precipitation: Conroe Montgomery Co. Airport, TX (5 mi away). Daylight is calculated from latitude.

ZIP codes in Conroe

773019a
20 to 25 °F
773029a
20 to 25 °F
773039a
20 to 25 °F
773049a
20 to 25 °F
773059a
20 to 25 °F
773069a
20 to 25 °F
773849a
20 to 25 °F
773859a
20 to 25 °F

Texas planting zones →

Questions about Conroe

What planting zone is Conroe, TX?

Conroe, TX is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Conroe, TX?

The median last spring frost is March 11 and the median first fall frost is November 19 (NOAA 1991–2020 normals, Conroe Montgomery Co. Airport station).

When can I plant a garden in Conroe, TX?

Cool-season crops like peas and spinach go in around Jan 28 – Feb 18; tomatoes, peppers, beans and squash after about Mar 18, once frost risk has passed.

What kind of onions grow in Conroe, TX?

Short-day onions: the longest day is 14 h 06 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

How much rain and snow does Conroe, TX get?

About 47.6 inches of precipitation a year (NOAA 1991–2020 normals).