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When to plant in Houston, TX

USDA Zone 9b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Houston, Texas — all computed from Houston's nearest NOAA weather station.

Houston enjoys a long ~326-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. In zone 9b, frost is a minor factor for Houston — most perennials thrive, and annual vegetables can go out early and stay late.

Station · HOUSTON-PORT · 11.4 km
Last spring frost
February 2
50% chance · 32°F
First fall frost
December 25
50% chance · 32°F
Growing season
326 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for HoustonA year-band showing 32°F frost risk from January to December for Houston: last spring frost around February 2, first fall frost around December 25, about 326 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

HOUSTON-PORT · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Houston’s own odds, recorded at HOUSTON-PORT.

Frost-probability curves for HoustonProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around February 2 and the first fall frost around December 25, giving about 326 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMar 16Feb 24Jan 22Nov 12Dec 2Jan 1
32°FMar 5Feb 2Dec 31Nov 27Dec 25Jan 21
28°FFeb 25Jan 23Dec 24Dec 8Jan 5Feb 9

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19

Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.

Add the next planting windows to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Houston, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 22 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

HOUSTON-PORT
Primary
11 km · 6 m elevation
SPRING
Feb 2
FALL
Dec 25
HOUSTON HOBBY AP
19 km · 13 m elevation
SPRING
Jan 30
FALL
Dec 28
HOUSTON INTERCONT AP
22 km · 29 m elevation
SPRING
Feb 13
FALL
Dec 9

Houston planting FAQ

When is the last spring frost in Houston, TX?

On average, the last spring frost in Houston is around February 2 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in Houston, TX?

The first fall frost in Houston typically arrives around December 25 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Houston in?

Houston is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Houston?

Houston has about 326 frost-free days — a long growing season — between the average last spring frost (February 2) and first fall frost (December 25).

When should I plant tomatoes in Houston?

For Houston, sow tomatoes indoors about December 8–December 22 and move the seedlings out around February 9, after the last spring frost.

Planting reminders

Never miss a window in Houston

An email when it’s time to start seeds, transplant, and sow — timed to Houston’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at HOUSTON-PORT, 11 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Houston, TX — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00414326. Retrieved from https://blissgarden.com/texas/houston.