Last spring frost
Apr 1
Frost Dates for Mertzon, TX
First fall frost
Nov 4
Growing season
215 days
Hardiness zone
8a
In an average year around Mertzon, TX, the last spring frost (32°F) is about Apr 1 and the first fall frost is about Nov 4, giving roughly a 215-day growing season. To be safe most years, wait until Mar 14 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 29 | Apr 12 | Mar 28 |
| Freeze (32°F) | Apr 19 | Apr 1 | Mar 14 |
| Hard (28°F) | Apr 7 | Mar 19 | Mar 2 |
| Severe (24°F) | Mar 28 | Mar 8 | Feb 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | Apr 23 | Apr 19 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 1 | Mar 28 |
| 32°F | Apr 19 | Apr 12 | Apr 8 | Apr 4 | Apr 1 | Mar 29 | Mar 25 | Mar 19 | Mar 14 |
| 28°F | Apr 7 | Apr 1 | Mar 28 | Mar 24 | Mar 19 | Mar 15 | Mar 11 | Mar 7 | Mar 2 |
| 24°F | Mar 28 | Mar 20 | Mar 16 | Mar 11 | Mar 8 | Mar 5 | Feb 28 | Feb 24 | Feb 15 |
| 20°F | Mar 16 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 18 | Feb 9 | Feb 1 | Jan 22 |
| 16°F | Mar 7 | Mar 1 | Feb 21 | Feb 9 | Feb 2 | Jan 27 | Jan 20 | Jan 11 | Dec 31 |
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 12 | Oct 26 | Nov 7 |
| Freeze (32°F) | Oct 21 | Nov 4 | Nov 18 |
| Hard (28°F) | Oct 29 | Nov 12 | Nov 30 |
| Severe (24°F) | Nov 7 | Nov 25 | Dec 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 12 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 7 |
| 32°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 18 |
| 28°F | Oct 29 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 24 | Nov 30 |
| 24°F | Nov 7 | Nov 12 | Nov 17 | Nov 21 | Nov 25 | Nov 28 | Dec 2 | Dec 6 | Dec 11 |
| 20°F | Nov 21 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 15 | Dec 21 | Dec 28 | Jan 5 |
| 16°F | Dec 1 | Dec 11 | Dec 19 | Dec 25 | Jan 1 | Jan 5 | Jan 12 | Jan 19 | Feb 2 |
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: Mertzon 12Nnw, Tx, about 13.2 miles away@if(!empty($station['elevation_ft'])), at 2,205 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 Mertzon, TX?
On average, the last spring frost (32°F) around Mertzon, TX is about Apr 1. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 14.
When is the first frost in the fall?
The first fall frost around Mertzon, TX typically arrives about Nov 4. 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 Apr 1 on average, or Mar 14 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 215 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 76941 Planting calendar → Texas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026