Last spring frost
Mar 6
Frost Dates for Knippa, TX
First fall frost
Nov 20
Growing season
263 days
Hardiness zone
9a
In an average year around Knippa, TX, the last spring frost (32°F) is about Mar 6 and the first fall frost is about Nov 20, giving roughly a 263-day growing season. To be safe most years, wait until Feb 9 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 9 | Mar 19 | Feb 28 |
| Freeze (32°F) | Mar 24 | Mar 6 | Feb 9 |
| Hard (28°F) | Mar 13 | Feb 21 | Jan 18 |
| Severe (24°F) | Mar 5 | Jan 31 | Dec 27 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 9 | Apr 2 | Mar 29 | Mar 24 | Mar 19 | Mar 15 | Mar 10 | Mar 5 | Feb 28 |
| 32°F | Mar 24 | Mar 17 | Mar 12 | Mar 8 | Mar 6 | Mar 2 | Feb 27 | Feb 21 | Feb 9 |
| 28°F | Mar 13 | Mar 7 | Mar 2 | Feb 26 | Feb 21 | Feb 13 | Feb 4 | Jan 28 | Jan 18 |
| 24°F | Mar 5 | Feb 25 | Feb 16 | Feb 6 | Jan 31 | Jan 24 | Jan 17 | Jan 7 | Dec 27 |
| 20°F | Mar 1 | Feb 13 | Feb 4 | Jan 27 | Jan 20 | Jan 11 | Jan 3 | Dec 29 | Dec 17 |
| 16°F | Feb 20 | Feb 3 | Jan 22 | Jan 13 | Jan 9 | Jan 5 | Jan 1 | Dec 25 | Dec 18 |
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 27 | Nov 11 | Nov 28 |
| Freeze (32°F) | Nov 3 | Nov 20 | Dec 8 |
| Hard (28°F) | Nov 12 | Dec 3 | Jan 1 |
| Severe (24°F) | Nov 23 | Dec 21 | Jan 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 13 | Nov 17 | Nov 21 | Nov 28 |
| 32°F | Nov 3 | Nov 8 | Nov 12 | Nov 17 | Nov 20 | Nov 24 | Nov 28 | Dec 3 | Dec 8 |
| 28°F | Nov 12 | Nov 19 | Nov 23 | Nov 29 | Dec 3 | Dec 7 | Dec 12 | Dec 21 | Jan 1 |
| 24°F | Nov 23 | Dec 1 | Dec 7 | Dec 13 | Dec 21 | Dec 27 | Jan 1 | Jan 7 | Jan 20 |
| 20°F | Dec 4 | Dec 12 | Dec 21 | Dec 28 | Jan 1 | Jan 5 | Jan 12 | Jan 23 | Feb 4 |
| 16°F | Dec 13 | Dec 22 | Dec 28 | Jan 1 | Jan 5 | Jan 10 | Jan 15 | Jan 31 | Feb 5 |
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: Hondo Muni Ap, Tx, about 26.8 miles away@if(!empty($station['elevation_ft'])), at 920 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 Knippa, TX?
On average, the last spring frost (32°F) around Knippa, TX is about Mar 6. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 9.
When is the first frost in the fall?
The first fall frost around Knippa, TX typically arrives about Nov 20. 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 6 on average, or Feb 9 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 263 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 78870 Planting calendar → Texas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026