Last spring frost
Mar 15
Frost Dates for Harper, TX
First fall frost
Nov 15
Growing season
243 days
Hardiness zone
8a
In an average year around Harper, TX, the last spring frost (32°F) is about Mar 15 and the first fall frost is about Nov 15, giving roughly a 243-day growing season. To be safe most years, wait until Feb 24 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 24 | Apr 1 | Mar 7 |
| Freeze (32°F) | Apr 12 | Mar 15 | Feb 24 |
| Hard (28°F) | Mar 28 | Mar 2 | Feb 5 |
| Severe (24°F) | Mar 12 | Feb 16 | Jan 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 24 | Apr 16 | Apr 10 | Apr 5 | Apr 1 | Mar 28 | Mar 22 | Mar 16 | Mar 7 |
| 32°F | Apr 12 | Apr 3 | Mar 28 | Mar 21 | Mar 15 | Mar 11 | Mar 5 | Mar 1 | Feb 24 |
| 28°F | Mar 28 | Mar 17 | Mar 11 | Mar 6 | Mar 2 | Feb 26 | Feb 22 | Feb 15 | Feb 5 |
| 24°F | Mar 12 | Mar 5 | Feb 28 | Feb 23 | Feb 16 | Feb 9 | Jan 31 | Jan 20 | Jan 3 |
| 20°F | Mar 4 | Feb 22 | Feb 13 | Feb 2 | Jan 25 | Jan 16 | Jan 7 | Dec 31 | Dec 18 |
| 16°F | Feb 22 | Feb 12 | Feb 3 | Jan 23 | Jan 15 | Jan 7 | Jan 3 | Dec 28 | Dec 19 |
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) | Oct 20 | Nov 4 | Nov 24 |
| Freeze (32°F) | Oct 27 | Nov 15 | Dec 6 |
| Hard (28°F) | Nov 4 | Nov 29 | Dec 25 |
| Severe (24°F) | Nov 14 | Dec 13 | Jan 18 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 20 | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 16 | Nov 24 |
| 32°F | Oct 27 | Nov 2 | Nov 6 | Nov 10 | Nov 15 | Nov 20 | Nov 24 | Nov 30 | Dec 6 |
| 28°F | Nov 4 | Nov 12 | Nov 18 | Nov 23 | Nov 29 | Dec 3 | Dec 7 | Dec 14 | Dec 25 |
| 24°F | Nov 14 | Nov 23 | Dec 1 | Dec 6 | Dec 13 | Dec 21 | Dec 30 | Jan 5 | Jan 18 |
| 20°F | Nov 27 | Dec 6 | Dec 18 | Dec 26 | Jan 1 | Jan 5 | Jan 12 | Jan 24 | Feb 12 |
| 16°F | Dec 10 | Dec 21 | Dec 31 | Jan 4 | Jan 7 | Jan 14 | Jan 23 | Feb 2 | Feb 17 |
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: Harper 3Ene, Tx, about 6.5 miles away@if(!empty($station['elevation_ft'])), at 2,110 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 Harper, TX?
On average, the last spring frost (32°F) around Harper, TX is about Mar 15. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 24.
When is the first frost in the fall?
The first fall frost around Harper, TX typically arrives about Nov 15. 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 Mar 15 on average, or Feb 24 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 243 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 78631 Planting calendar → Texas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026