Frost dates for 78237 — San Antonio, TX
How San Antonio compares
- In 8 years out of 10, the last spring frost in San Antonio falls between January 16 and March 12, a 55-day window. The first fall frost falls between November 13 and December 25.
- The median last frost is 21 days earlier than the Texas median of Mar 15.
- Its 283-day growing season is longer than 89% of the 1,316 Texas places with a regular frost season (state median 245 days).
- The last frost is 9 days earlier than the zone 9a median of Mar 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 9a chart.
- The weather station records an average of 14 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | January 16 |
| 50% (median) | February 22 |
| 10% (safe for tender plants) | March 12 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 13 |
| 50% (median) | December 2 |
| 90% (late) | December 25 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for San Antonio, TX
Frost dates for 78237 — San Antonio, TX — last frost Feb 22, first frost Dec 2, zone 9a. whenisthelastfrost.com
When to plant vegetables in San Antonio, TX
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 30 – Dec 14 | Jan 25 – Feb 8 | — | — |
| Peppers | Dec 14 – Dec 28 | Mar 8 – Mar 22 | — | — |
| Eggplant | Dec 14 – Dec 28 | Mar 8 – Mar 22 | — | — |
| Tomatoes | Dec 28 – Jan 11 | Mar 1 – Mar 15 | — | — |
| Lettuce | Dec 28 – Jan 11 | Feb 1 – Feb 15 | Jan 25 – Mar 1 | Oct 7 – Nov 4 |
| Kale | Dec 28 – Jan 11 | Jan 25 – Feb 8 | Jan 25 – Feb 8 | Sep 23 – Oct 14 |
| Broccoli | Dec 28 – Jan 11 | Feb 8 – Feb 22 | — | Aug 26 – Sep 16 |
| Cabbage | Dec 28 – Jan 11 | Feb 1 – Feb 15 | — | Aug 26 – Sep 16 |
| Cauliflower | Dec 28 – Jan 11 | Feb 8 – Feb 22 | — | Aug 26 – Sep 16 |
| Okra | Jan 11 – Jan 25 | Mar 15 – Mar 29 | Mar 15 – Mar 29 | — |
| Basil | Jan 11 – Jan 25 | Mar 1 – Mar 15 | — | — |
| Peas | — | — | Jan 11 – Feb 1 | Sep 9 – Sep 30 |
| Spinach | — | — | Jan 11 – Feb 1 | Oct 7 – Oct 28 |
| Radishes | — | — | Jan 18 – Mar 1 | Oct 21 – Nov 11 |
| Cucumbers | Jan 25 – Feb 1 | Mar 8 – Mar 15 | Mar 1 – Mar 15 | Sep 16 – Sep 30 |
| Zucchini & Summer Squash | Jan 25 – Feb 1 | — | Mar 1 – Mar 15 | Sep 23 – Oct 7 |
| Winter Squash & Pumpkins | Jan 25 – Feb 1 | — | Mar 1 – Mar 15 | — |
| Melons & Watermelon | Jan 25 – Feb 1 | Mar 8 – Mar 22 | — | — |
| Carrots | — | — | Feb 1 – Mar 1 | Sep 9 – Sep 23 |
| Beets | — | — | Feb 1 – Mar 1 | Sep 23 – Oct 7 |
| Potatoes | — | — | Feb 1 – Feb 22 | — |
| Swiss Chard | — | — | Feb 8 – Mar 8 | Sep 23 – Oct 7 |
| Cilantro | — | — | Feb 8 – Mar 1 | Oct 7 – Oct 28 |
| Green Beans | — | — | Mar 1 – Mar 22 | Sep 16 – Sep 30 |
| Sweet Corn | — | — | Mar 1 – Mar 15 | — |
| Sweet Potatoes | — | Mar 8 – Mar 29 | — | — |
| Garlic | — | — | — | Nov 18 – Dec 23 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the San Antonio Kelly Afb, TX weather station, 5 km away (elevation 682 ft (208 m)).
ZIP codes in San Antonio: 78201 78202 78203 78204 78205 78206 78207 78208 78209 78210 78211 78212 78213 78214 78215 78216 78217 78218 78219 78220 78221 78222 78223 78224 78225 78226 78227 78228 78229 78230 78231 78232 78233 78235 78237 78238 78239 78240 78241 78242 78243 78244 78245 78246 78247 78248 78249 78250 78251 78252 78253 78254 78255 78256 78257 78258 78259 78260 78261 78263 …
Frost dates near San Antonio
- Jbsa Ft Sam Houston Feb 25 · Nov 28
- Jbsa Lackland Feb 25 · Nov 28
- Macdona Feb 22 · Dec 2
- Von Ormy Feb 22 · Dec 2
- Atascosa Feb 24 · Dec 2
- Somerset Feb 24 · Dec 2
- Converse Feb 21 · Dec 5
- La Coste Feb 24 · Dec 2
Frequently asked questions
When is the last frost in San Antonio, TX?
The median last spring frost in San Antonio, TX is February 22. There is still about a 10% chance of frost after March 12, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Antonio, TX?
The median first fall frost is December 2, with about a 10% chance of frost before November 13.
How long is the growing season in San Antonio, TX?
About 283 days between the median last spring frost and first fall frost.
What planting zone is San Antonio, TX?
San Antonio, TX is in USDA hardiness zone 9a.