Metro areas

Gardening in Houston-Pasadena-The Woodlands, TX

This metro spans USDA zones 9a to 10a, so there is no single zone for Houston-Pasadena-The Woodlands, TX and anyone who gives you one is rounding. 75% of its ZIP codes are zone 9b; the rest are not.

USDA zones 9a–10a 3 zones across 243 ZIP codes
ZIP codes 243 243 have a NOAA station within range
Weather stations 30 NOAA 1991–2020 normals, across 8,839 sq mi

Which zone you are in depends where you are

Houston-Pasadena-The Woodlands, TX covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 75% in zone 9b and wrong for the other 25%. Here is the actual split.

Zone ZIP codes Share  
9b 182 75%
9a 55 23%
10a 6 2%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

No freeze range is shown for Houston-Pasadena-The Woodlands, TX, because the freeze window here crosses New Year, so an earliest-to-latest range would be arithmetic on dates that do not sit in order. The tools below still answer for individual ZIP codes here, and will say what applies.

Your growing season

NOAA publishes a growing-season length for each station, and across the 30 stations serving Houston-Pasadena-The Woodlands, TX it runs 253–365 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 89–96 °F , at or above the 90 °F point where cool-season crops bolt and tomato and pepper pollen fails — so midsummer sowings of lettuce and its relatives are worth holding here.

What survives the winter changes across Houston-Pasadena-The Woodlands, TX

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 46 come through the winter in zone 9a and only 25 in zone 10a. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
9a 55 46 of 74 25
9b 182 40 of 74 32
10a 6 25 of 74 49

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 30 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Alvin, TX USC00410204 February 14 December 5 298 days
Anahuac, TX USC00410235 February 12 December 6 302 days
Angleton 2 W, TX USC00410257 January 29 December 31 333 days
Angleton Brazoria AP, TX USW00012976 February 13 December 8 301 days
Bay City Wtr Wks, TX USC00410569 February 20 December 3 290 days
Baytown, TX USC00410586 February 20 December 4 292 days
Bellville 6Nne, TX USC00410655 February 28 December 2 279 days
Brenham, TX USC00411048 March 2 November 30 273 days
Cleveland, TX USC00411810 March 7 November 20 259 days
Columbus, TX USC00411911 March 9 November 20 255 days
Conroe Montgomery Co AP, TX USW00053902 March 11 November 19 253 days
Conroe, TX USC00411956 February 24 December 2 285 days
Freeport 2 NW, TX USC00413340 January 27 January 1 338 days
Galveston Scholes FLD, TX USW00012923 January 18 January 7 365 days
Galveston, TX USW00012944 January 25 January 1 348 days
Houston Clover FLD, TX USW00012975 January 31 December 27 328 days
Houston Hobby AP, TX USW00012918 January 30 December 28 330 days
Houston Hooks Mem AP, TX USW00053910 February 19 December 3 290 days
Houston Intercont AP, TX USW00012960 February 13 December 9 300 days
Houston Nwso, TX USC00414333 January 31 December 14 317 days
Houston Sugarland Mem, TX USW00012977 February 2 December 11 318 days
Houston-Port, TX USC00414326 February 2 December 25 327 days
Huntsville Muni AP, TX USW00053903 March 2 November 26 272 days
Huntsville, TX USC00414382 March 1 November 28 272 days
Liberty, TX USC00415196 February 21 December 1 286 days
Livingston 2 Nne, TX USC00415271 March 1 November 24 269 days
Sealy, TX USC00418160 February 28 November 30 276 days
Sugar Land, TX USC00418728 February 9 December 13 305 days
Thompsons 3 Wsw, TX USC00418996 February 15 December 6 297 days
Wildwood, TX USC00419754 March 6 November 21 261 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

All metro areas