Frost dates for 78338Armstrong, TX
The average last spring frost in Armstrong is February 22 and the average first fall frost is December 5, giving a typical growing season of about 293 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 22
- Average first fall frost
- Dec 5
- Growing season
- 293 days
Safer after Mar 14 (1-in-10 risk)
Possible by Nov 15 (1-in-10 risk)
First frost typically in 35 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) | Feb 8 · Mar 6 · Mar 27 | Nov 5 · Nov 24 · Dec 18 | 263 days | 100% |
| Frost / freeze (32°F) | Jan 19 · Feb 22 · Mar 14 | Nov 15 · Dec 5 · Jan 6 | 293 days | 99% |
| Hard freeze (28°F) | Dec 22 · Jan 31 · Mar 8 | Nov 25 · Dec 22 · Feb 4 | 331 days | 84% |
Planting calendar for Armstrong
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 | Jan 22 – Mar 30 |
| Tomatoes | Transplant outdoors | Mar 10 – Aug 15 |
| Peppers | Start seeds indoors | Jan 22 – Feb 22 |
| Peppers | Transplant outdoors | Mar 24 – Apr 24 |
| Eggplant | Start seeds indoors | Feb 8 – Mar 9 |
| Eggplant | Transplant outdoors | Mar 24 – Apr 24 |
| Cucumbers | Sow outdoors | Mar 24 – Aug 25 |
| Summer squash | Sow outdoors | Mar 10 – Apr 24 |
| Winter squash & pumpkins | Sow outdoors | Mar 24 – Apr 24 |
| Snap beans | Sow outdoors | Mar 10 – Sep 17 |
| Sweet corn | Sow outdoors | Mar 10 – Aug 15 |
| Watermelon & cantaloupe | Sow outdoors | Mar 24 – Apr 24 |
| Okra | Sow outdoors | Mar 17 – Apr 9 |
| Peas | Sow outdoors (spring) | Jan 22 – Mar 9 |
| Potatoes | Plant outdoors (spring) | Jan 22 – Mar 24 |
| Onions | Start seeds indoors (spring) | Dec 11 – Jan 7 |
| Onions | Transplant outdoors (spring) | Feb 8 – Mar 9 |
| Broccoli | Start seeds indoors (spring) | Jan 4 – Feb 7 |
| Broccoli | Transplant outdoors (spring) | Feb 8 – Mar 9 |
| Broccoli | Start seeds indoors (fall) | Aug 5 – Aug 15 |
| Broccoli | Transplant outdoors (fall) | Sep 4 – Sep 15 |
| Cabbage | Start seeds indoors (spring) | Dec 25 – Jan 22 |
| Cabbage | Transplant outdoors (spring) | Jan 22 – Feb 22 |
| Cabbage | Start seeds indoors (fall) | Jul 26 – Aug 25 |
| Cabbage | Transplant outdoors (fall) | Aug 25 – Sep 25 |
| Leaf lettuce | Sow outdoors (spring) | Jan 22 – Apr 9 |
| Leaf lettuce | Sow outdoors (fall) | Aug 25 – Oct 11 |
| Spinach | Sow outdoors (spring) | Jan 15 – Feb 28 |
| Spinach | Sow outdoors (fall) | Sep 11 – Oct 16 |
| Radishes | Sow outdoors (spring) | Jan 22 – Mar 14 |
| Radishes | Sow outdoors (fall) | Aug 25 – Oct 26 |
| Kale | Sow outdoors (spring) | Feb 8 – Feb 28 |
| Kale | Sow outdoors (fall) | Aug 18 – Sep 25 |
| Carrots | Sow outdoors (spring) | Feb 22 – Apr 9 |
| Carrots | Sow outdoors (fall) | Jul 26 – Sep 10 |
| Garlic | Plant outdoors (fall) | Nov 25 – Dec 26 |
Where these dates come from
ZIP code 78338 is matched to the NOAA station Armstrong 4Se, TX, 7.3 km away, at 25 ft elevation (9 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Armstrong 4Se, TX (used) | 25 ft | Feb 22 | Dec 5 |
| Sarita 7 E, TX | 38 ft | Feb 17 | Dec 8 |
| Raymondville, TX | 31 ft | Jan 21 | Dec 26 |
| Falfurrias, TX | 139 ft | Feb 25 | Dec 1 |
Frost dates near Armstrong
- Sarita, TX 78385 · last Feb 25, first Dec 1
- Encino, TX 78353 · last Feb 25, first Dec 1
- San Perlita, TX 78590 · last Jan 21, first Dec 26
- Raymondville, TX 78580 · last Jan 21, first Dec 26
- Lasara, TX 78561 · last Jan 21, first Dec 26
- Port Mansfield, TX 78598 · last Jan 12, first Jan 1
- Riviera, TX 78379 · last Feb 3, first Dec 14
- Lyford, TX 78569 · last Jan 21, first Dec 26
Frequently asked questions
- When is the last frost in Armstrong, TX?
- For ZIP code 78338, the average last spring frost (32°F) is February 22, based on NOAA 1991-2020 climate normals for the Armstrong 4Se, TX weather station. There is a 1-in-10 chance of a frost after March 14.
- When is the first frost in Armstrong, TX?
- The average first fall frost (32°F) is December 5. There is a 1-in-10 chance of frost by November 15, so tender plants are at risk from that point on.
- How long is the growing season in 78338?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 293 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.