Frost Dates for San Antonio, TX 78245

Last spring frost February 28 · First fall frost November 25 · 270 frost-free days · USDA Zone 9a

Frost probability for 78245

Frost	10%	50%	90%
Spring (last frost)	March 23	February 28	February 6
Fall (first frost)	November 8	November 25	December 13

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (29.1 km away); the 50% date is the median year.

Frost dates by ZIP code in San Antonio, TX

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
78245	February 28	November 25	9a
78254	February 28	November 25	9a
78253	February 28	November 25	9a
78249	March 4	November 21	9a
78251	February 28	November 25	9a
78223	February 28	November 25	9a
78240	March 4	November 21	9a
78250	February 28	November 25	9a
78228	February 28	November 25	9a
78207	February 28	November 25	9a
78258	March 4	November 21	9a
78247	February 28	November 25	9a
78233	February 28	November 25	9a
78227	February 28	November 25	9a
78209	March 4	November 21	9a
78221	February 28	November 25	9a
78201	March 4	November 21	9a
78230	March 4	November 21	9a
78216	March 4	November 21	9a
78213	March 4	November 21	9a
78218	February 28	November 25	9a
78244	March 4	November 21	9a
78260	March 4	November 21	8b
78237	February 28	November 25	9a
78232	March 4	November 21	9a
78242	February 28	November 25	9a
78229	March 4	November 21	9a
78210	February 28	November 25	9a
78217	February 28	November 25	9a
78211	February 28	November 25	9a
78259	February 28	November 25	9a
78239	February 28	November 25	9a
78212	March 4	November 21	9a
78261	February 28	November 25	9a
78222	March 4	November 21	9a
78238	February 28	November 25	9a
78224	February 28	November 25	9a
78214	February 28	November 25	9a
78252	February 28	November 25	9a
78220	March 4	November 21	9a
78219	March 4	November 21	9a
78255	March 4	November 21	8b
78248	March 4	November 21	9a
78256	March 4	November 21	9a
78225	February 28	November 25	9a
78204	February 28	November 25	9a
78264	February 28	November 25	9a
78257	March 4	November 21	9a
78202	February 28	November 25	9a
78231	March 4	November 21	9a
78266	February 28	November 25	9a
78226	February 28	November 25	9a
78203	February 28	November 25	9a
78263	March 4	November 21	9a
78208	March 4	November 21	9a
78215	February 28	November 25	9a
78235	February 28	November 25	9a
78205	February 28	November 25	9a
78243	February 28	November 25	9a

Month by month in San Antonio

Month	What to do
January	Start herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
February	Last frost around February 28. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
March	Frost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
April	Succession plant lettuce and greens. Keep beds weeded and watered consistently.
May	Harvest regularly to encourage production. Monitor for pests and disease.
June	Midsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
July	Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
August	Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
September	Direct sow carrots and beets for fall harvest. Start fall broccoli and kale indoors.
October	First fall frost approaching (around November 25). Transplant fall brassicas. Sow spinach, arugula, and radishes.
November	First frost around November 25. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
December	Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.

What grows in a 270-day season

Frequently Asked Questions

What is the last frost date for San Antonio, TX (ZIP 78245)?

The median last spring frost date for San Antonio, TX (ZIP code 78245) is around February 28. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in San Antonio, TX?

The median first fall frost date for San Antonio, TX is around November 25. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in San Antonio, TX?

The frost-free growing season in San Antonio is about 270 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is San Antonio, TX?

Based on frost date patterns, San Antonio falls approximately in 9a. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in San Antonio, TX?

Start tomato seeds indoors 6–8 weeks before your last frost date (around February 28). For San Antonio, that's roughly January 3 to January 17. Transplant outdoors 1–2 weeks after your last frost.