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When to plant in Iowa Colony, TX

USDA Zone 9b

Iowa Colony, Texas frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

With about 330 frost-free days, Iowa Colony supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Iowa Colony's nearest full-normals station sits about 20 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. In zone 9b, frost is a minor factor for Iowa Colony — most perennials thrive, and annual vegetables can go out early and stay late.

Station · HOUSTON CLOVER FLD · 19.6 km
Last spring frost
January 31
50% chance · 32°F
First fall frost
December 27
50% chance · 32°F
Growing season
330 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Iowa ColonyA year-band showing 32°F frost risk from January to December for Iowa Colony: last spring frost around January 31, first fall frost around December 27, about 330 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in Iowa Colony is now 11 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

HOUSTON CLOVER FLD · 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 Iowa Colony’s own odds, recorded at HOUSTON CLOVER FLD.

Frost-probability curves for Iowa ColonyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 31 and the first fall frost around December 27, giving about 330 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 18Feb 21Jan 23Nov 13Dec 3Jan 2
32°FMar 5Jan 31Jan 1Nov 28Dec 27Jan 28
28°FFeb 20Jan 18Dec 22Dec 14Jan 8Feb 4

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 Iowa Colony, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 21 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 CLOVER FLD
Primary
20 km · 13 m elevation
SPRING
Jan 31
FALL
Dec 27
ALVIN
20 km · 9 m elevation
SPRING
Feb 14
FALL
Dec 5
THOMPSONS 3 WSW
21 km · 21 m elevation
SPRING
Feb 15
FALL
Dec 6

Iowa Colony planting FAQ

When is the last spring frost in Iowa Colony, TX?

Iowa Colony's average last spring frost falls near January 31 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.

When is the first fall frost in Iowa Colony, TX?

In Iowa Colony, the first 32°F freeze of fall lands around December 27 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Iowa Colony in?

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

How long is the growing season in Iowa Colony?

Iowa Colony has about 330 frost-free days — a long growing season — between the average last spring frost (January 31) and first fall frost (December 27).

When should I plant tomatoes in Iowa Colony?

For Iowa Colony, sow tomatoes indoors about December 6–December 20 and move the seedlings out around February 7, after the last spring frost.

Planting reminders

Never miss a window in Iowa Colony

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

Nearby cities

8 within reach

Frost dates recorded at HOUSTON CLOVER FLD, 20 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 Iowa Colony, TX — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00012975. Retrieved from https://blissgarden.com/texas/iowa-colony.