San Antonio frost dates and planting season

Name: San Antonio
Address: Texas, United States

When to plant vegetables here. Cover calendars (fleece, cold frame, unheated greenhouse) are on each plant’s when-to-plant page.

San Antonio is frost-free here (frost in fewer than about 1 winter in 10). Growing windows follow temperature limits, not frost dates. Plant cool-season crops after about October 26; wait until about February 23 for warm-season crops.

Frost-free days365all year (frost-free)

Cover calendars (fleece, cold frame, unheated greenhouse) live on each crop’s when-to-plant page.

Weekly possible temperature7 – 105 °F

Frost-free daysall year (frost-free)

Days suitable for warm-season vegetables175 (February 23 – May 31; September 28 – December 13)

Days suitable for cool-season vegetables155 (October 26 – March 29 (continues into next year))

Calculated by Plan & Plant · Method · Data 2019–2026

Frost and suitability dates are typical figures from climate statistics. Microclimates vary; they are not a guarantee.

Frost dates calculated by Plan & Plant from Weather data by Open-Meteo.com (CC BY 4.0). Local frost pockets, valleys and coastal sites can differ by 1–3 weeks.

How we calculated this

Data: ERA5-Land via Open-Meteo, cell 29.42, -98.49, years 2019–2026 (not a 30-year climate normal yet).
Typical and safer dates: Typical last frost is the date after which half of winters in this sample had no more frost; safer is later in the sample so fewer winters still frosted.
Confidence: Provisional — short or thin sample for this place.
Full methodology (algorithm 2026-10-season-6).

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What to plant when

Cool-season vegetables

Earliest outdoor start: October 26

Suitable window: October 26 – March 29 (continues into next year)

Cool-season crops prefer cooler weather.

See cool-season details

Warm-season vegetables

Earliest outdoor start: February 23

Suitable window: February 23 – May 31; September 28 – December 13

Warm-season crops need mild or warm weather and cannot take frost.

Frost kills these crops, and cold snaps set them back.

See warm-season details

Green = usually good weeks to grow; blue or gray = usually too cold for that crop type.

Starter plants for San Antonio

Cool-season

Radish Sow: January 23 – April 5; October 28 – November 29 Planting dates
Arugula Sow: January 23 – April 5; October 28 – November 16 Planting dates
Spinach Sow: January 23 – April 5 Planting dates
Lettuce Sow: January 23 – April 5 Planting dates
Kale Sow: January 23 – March 19 Planting dates
Beet Sow: February 6 – October 9 Planting dates

Warm-season

Zucchini Sow: March 20 – May 14 Planting dates
Cucumber Sow: March 20 – May 14 Planting dates
Green bean Sow: March 6 – September 18 Planting dates
Tomato Transplant: March 20 – May 14 Start indoors, then transplant. Planting dates
Bell pepper Transplant: March 20 – May 14 Start indoors, then transplant. Planting dates

How these dates are judged

Last frost: The typical last spring date when frost is still expected.
First frost: The typical first fall date when frost returns.
Frost-free days: The approximate days between those two dates.
Cool-season vegetables: Crops that prefer cooler weather, such as lettuce, kale, peas, and radish.
Warm-season vegetables: Crops that need warm weather and cannot take frost, such as tomato, pepper, squash, and beans.

Cool-season planting window

Oct 26 – Mar 29 (155 days)

Warm-season planting window

Feb 23 – May 31; Sep 28 – Dec 13 (175 days)

Weekly temperatures and planting windows

Temperatures across the year for San Antonio, with cool- and warm-season weeks and frost dates.

Possible min to max
Average min to max
Suitable
Tolerable
Too cold
Too hot

Selected week · tap a week or use the arrows

Week 44 · Oct 26 – Nov 1

Average 58 to 77 °F · Possible 42 to 90 °F

Cool season: tolerable

Warm season: tolerable

A week is suitable for a crop type when its average low and high sit inside that type's range and its possible readings stay within the frost and heat limits (cool: 28 °F to 81 °F, warm: 32 °F to 90 °F); crossing a limit makes it tolerable, and for warm crops any chance of frost makes it too cold.

Based on average frost dates.

Texas, United States · 29.42412, -98.49363 · 2026

Coldest weekly possible temperature7 °F

Hottest weekly possible temperature105 °F

Last expected spring frost

First expected fall frost

Show all 53 weeks