Last spring frost
Feb 26
Frost Dates for Castle Hills, TX
First fall frost
Nov 28
Growing season
277 days
Hardiness zone
9a
In an average year around Castle Hills, TX, the last spring frost (32°F) is about Feb 26 and the first fall frost is about Nov 28, giving roughly a 277-day growing season. To be safe most years, wait until Jan 29 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Apr 2 | Mar 10 | Feb 20 |
| Freeze (32°F) | Mar 17 | Feb 26 | Jan 29 |
| Hard (28°F) | Mar 7 | Feb 9 | Jan 2 |
| Severe (24°F) | Feb 26 | Jan 22 | Dec 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 2 | Mar 25 | Mar 20 | Mar 14 | Mar 10 | Mar 7 | Mar 3 | Feb 27 | Feb 20 |
| 32°F | Mar 17 | Mar 10 | Mar 6 | Mar 2 | Feb 26 | Feb 21 | Feb 16 | Feb 8 | Jan 29 |
| 28°F | Mar 7 | Feb 28 | Feb 21 | Feb 15 | Feb 9 | Feb 1 | Jan 26 | Jan 18 | Jan 2 |
| 24°F | Feb 26 | Feb 15 | Feb 7 | Jan 31 | Jan 22 | Jan 14 | Jan 7 | Dec 30 | Dec 17 |
| 20°F | Feb 16 | Feb 6 | Jan 30 | Jan 21 | Jan 11 | Jan 5 | Jan 2 | Dec 30 | Dec 17 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Nov 1 | Nov 16 | Dec 5 |
| Freeze (32°F) | Nov 7 | Nov 28 | Dec 22 |
| Hard (28°F) | Nov 21 | Dec 13 | Jan 19 |
| Severe (24°F) | Dec 2 | Jan 1 | Feb 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 1 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 21 | Nov 24 | Nov 29 | Dec 5 |
| 32°F | Nov 7 | Nov 15 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 11 | Dec 22 |
| 28°F | Nov 21 | Nov 28 | Dec 3 | Dec 7 | Dec 13 | Dec 21 | Dec 30 | Jan 6 | Jan 19 |
| 24°F | Dec 2 | Dec 10 | Dec 18 | Dec 26 | Jan 1 | Jan 6 | Jan 13 | Jan 24 | Feb 10 |
| 20°F | Dec 14 | Dec 22 | Dec 30 | Jan 2 | Jan 6 | Jan 13 | Jan 23 | Feb 2 | Feb 10 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: San Antonio Intl Ap, Tx, about 3 miles away@if(!empty($station['elevation_ft'])), at 789 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Castle Hills, TX?
On average, the last spring frost (32°F) around Castle Hills, TX is about Feb 26. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 29.
When is the first frost in the fall?
The first fall frost around Castle Hills, TX typically arrives about Nov 28. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Feb 26 on average, or Jan 29 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 277 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 78213 Planting calendar → Texas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026