Frost dates for 76666Mertens, TX
The average last spring frost in Mertens is March 21 and the average first fall frost is November 10, giving a typical growing season of about 235 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 21
- Average first fall frost
- Nov 10
- Growing season
- 235 days
Safer after Apr 8 (1-in-10 risk)
Possible by Oct 28 (1-in-10 risk)
First frost typically in 14 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Mar 14 · Apr 2 · Apr 19 | Oct 21 · Nov 3 · Nov 17 | 213 days | 100% |
| Frost / freeze (32°F) | Mar 2 · Mar 21 · Apr 8 | Oct 28 · Nov 10 · Nov 29 | 235 days | 100% |
| Hard freeze (28°F) | Feb 17 · Mar 9 · Mar 29 | Nov 2 · Nov 22 · Dec 14 | 257 days | 100% |
Planting calendar for Mertens
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Feb 18 – Apr 26 |
| Tomatoes | Transplant outdoors | Apr 6 – Jul 21 |
| Peppers | Start seeds indoors | Feb 18 – Mar 21 |
| Peppers | Transplant outdoors | Apr 20 – May 21 |
| Eggplant | Start seeds indoors | Mar 7 – Apr 5 |
| Eggplant | Transplant outdoors | Apr 20 – May 21 |
| Cucumbers | Sow outdoors | Apr 20 – Jul 31 |
| Summer squash | Sow outdoors | Apr 6 – May 21 |
| Winter squash & pumpkins | Sow outdoors | Apr 20 – May 21 |
| Snap beans | Sow outdoors | Apr 6 – Aug 23 |
| Sweet corn | Sow outdoors | Apr 6 – Jul 21 |
| Watermelon & cantaloupe | Sow outdoors | Apr 20 – May 21 |
| Okra | Sow outdoors | Apr 13 – May 6 |
| Peas | Sow outdoors (spring) | Feb 18 – Apr 5 |
| Potatoes | Plant outdoors (spring) | Feb 18 – Apr 20 |
| Onions | Start seeds indoors (spring) | Jan 7 – Feb 3 |
| Onions | Transplant outdoors (spring) | Mar 7 – Apr 5 |
| Broccoli | Start seeds indoors (spring) | Jan 31 – Mar 6 |
| Broccoli | Transplant outdoors (spring) | Mar 7 – Apr 5 |
| Broccoli | Start seeds indoors (fall) | Jul 11 – Jul 21 |
| Broccoli | Transplant outdoors (fall) | Aug 10 – Aug 21 |
| Cabbage | Start seeds indoors (spring) | Jan 21 – Feb 18 |
| Cabbage | Transplant outdoors (spring) | Feb 18 – Mar 21 |
| Cabbage | Start seeds indoors (fall) | Jul 1 – Jul 31 |
| Cabbage | Transplant outdoors (fall) | Jul 31 – Aug 31 |
| Leaf lettuce | Sow outdoors (spring) | Feb 18 – May 6 |
| Leaf lettuce | Sow outdoors (fall) | Jul 31 – Sep 16 |
| Spinach | Sow outdoors (spring) | Feb 11 – Mar 27 |
| Spinach | Sow outdoors (fall) | Aug 17 – Sep 21 |
| Radishes | Sow outdoors (spring) | Feb 18 – Apr 10 |
| Radishes | Sow outdoors (fall) | Jul 31 – Oct 1 |
| Kale | Sow outdoors (spring) | Mar 7 – Mar 27 |
| Kale | Sow outdoors (fall) | Jul 24 – Aug 31 |
| Carrots | Sow outdoors (spring) | Mar 21 – May 6 |
| Carrots | Sow outdoors (fall) | Jul 1 – Aug 16 |
| Garlic | Plant outdoors (fall) | Oct 31 – Dec 1 |
Where these dates come from
ZIP code 76666 is matched to the NOAA station Hillsboro, TX, 20 km away, at 550 ft elevation (24 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hillsboro, TX (used) | 550 ft | Mar 21 | Nov 10 |
| Navarro Mills Dam, TX | 454 ft | Mar 13 | Nov 14 |
| Bardwell Dam, TX | 461 ft | Mar 8 | Nov 21 |
| Corsicana, TX | 449 ft | Mar 14 | Nov 16 |
Frost dates near Mertens
- Irene, TX 76650 · last Mar 13, first Nov 14
- Brandon, TX 76628 · last Mar 21, first Nov 10
- Bynum, TX 76631 · last Mar 21, first Nov 10
- Malone, TX 76660 · last Mar 13, first Nov 14
- Frost, TX 76641 · last Mar 13, first Nov 14
- Milford, TX 76670 · last Mar 21, first Nov 10
- Italy, TX 76651 · last Mar 21, first Nov 10
- Blooming Grove, TX 76626 · last Mar 13, first Nov 14
Frequently asked questions
- When is the last frost in Mertens, TX?
- For ZIP code 76666, the average last spring frost (32°F) is March 21, based on NOAA 1991-2020 climate normals for the Hillsboro, TX weather station. There is a 1-in-10 chance of a frost after April 8.
- When is the first frost in Mertens, TX?
- The average first fall frost (32°F) is November 10. There is a 1-in-10 chance of frost by October 28, so tender plants are at risk from that point on.
- How long is the growing season in 76666?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 235 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.