Frost dates for 78066Rio Medina, TX
The average last spring frost in Rio Medina is February 28 and the average first fall frost is November 27, giving a typical growing season of about 274 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 28
- Average first fall frost
- Nov 27
- Growing season
- 274 days
Safer after Mar 17 (1-in-10 risk)
Possible by Nov 8 (1-in-10 risk)
First frost typically in 31 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 22 · Mar 11 · Mar 31 | Nov 1 · Nov 16 · Dec 3 | 249 days | 100% |
| Frost / freeze (32°F) | Feb 3 · Feb 28 · Mar 17 | Nov 8 · Nov 27 · Dec 18 | 274 days | 100% |
| Hard freeze (28°F) | Jan 16 · Feb 12 · Mar 7 | Nov 17 · Dec 9 · Jan 11 | 305 days | 99% |
Planting calendar for Rio Medina
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 28 – Apr 5 |
| Tomatoes | Transplant outdoors | Mar 16 – Aug 7 |
| Peppers | Start seeds indoors | Jan 28 – Feb 28 |
| Peppers | Transplant outdoors | Mar 30 – Apr 30 |
| Eggplant | Start seeds indoors | Feb 14 – Mar 15 |
| Eggplant | Transplant outdoors | Mar 30 – Apr 30 |
| Cucumbers | Sow outdoors | Mar 30 – Aug 17 |
| Summer squash | Sow outdoors | Mar 16 – Apr 30 |
| Winter squash & pumpkins | Sow outdoors | Mar 30 – Apr 30 |
| Snap beans | Sow outdoors | Mar 16 – Sep 9 |
| Sweet corn | Sow outdoors | Mar 16 – Aug 7 |
| Watermelon & cantaloupe | Sow outdoors | Mar 30 – Apr 30 |
| Okra | Sow outdoors | Mar 23 – Apr 15 |
| Peas | Sow outdoors (spring) | Jan 28 – Mar 15 |
| Potatoes | Plant outdoors (spring) | Jan 28 – Mar 30 |
| Onions | Start seeds indoors (spring) | Dec 17 – Jan 13 |
| Onions | Transplant outdoors (spring) | Feb 14 – Mar 15 |
| Broccoli | Start seeds indoors (spring) | Jan 10 – Feb 13 |
| Broccoli | Transplant outdoors (spring) | Feb 14 – Mar 15 |
| Broccoli | Start seeds indoors (fall) | Jul 28 – Aug 7 |
| Broccoli | Transplant outdoors (fall) | Aug 27 – Sep 7 |
| Cabbage | Start seeds indoors (spring) | Dec 31 – Jan 28 |
| Cabbage | Transplant outdoors (spring) | Jan 28 – Feb 28 |
| Cabbage | Start seeds indoors (fall) | Jul 18 – Aug 17 |
| Cabbage | Transplant outdoors (fall) | Aug 17 – Sep 17 |
| Leaf lettuce | Sow outdoors (spring) | Jan 28 – Apr 15 |
| Leaf lettuce | Sow outdoors (fall) | Aug 17 – Oct 3 |
| Spinach | Sow outdoors (spring) | Jan 21 – Mar 6 |
| Spinach | Sow outdoors (fall) | Sep 3 – Oct 8 |
| Radishes | Sow outdoors (spring) | Jan 28 – Mar 20 |
| Radishes | Sow outdoors (fall) | Aug 17 – Oct 18 |
| Kale | Sow outdoors (spring) | Feb 14 – Mar 6 |
| Kale | Sow outdoors (fall) | Aug 10 – Sep 17 |
| Carrots | Sow outdoors (spring) | Feb 28 – Apr 15 |
| Carrots | Sow outdoors (fall) | Jul 18 – Sep 2 |
| Garlic | Plant outdoors (fall) | Nov 17 – Dec 18 |
Where these dates come from
ZIP code 78066 is matched to the NOAA station Hondo, TX, 29.5 km away, at 879 ft elevation (7 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hondo, TX (used) | 879 ft | Feb 28 | Nov 27 |
| San Antonio/Seaworld, TX | 940 ft | Feb 18 | Dec 9 |
| Lytle 3W, TX | 722 ft | Feb 24 | Dec 2 |
| San Antonio Kelly Afb, TX | 682 ft | Feb 22 | Dec 2 |
Frost dates near Rio Medina
- Mico, TX 78056 · last Mar 6, first Nov 20
- San Antonio, TX 78253 · last Feb 18, first Dec 9
- Castroville, TX 78009 · last Feb 28, first Nov 27
- La Coste, TX 78039 · last Feb 24, first Dec 2
- Helotes, TX 78023 · last Mar 15, first Nov 13
- Macdona, TX 78054 · last Feb 20, first Dec 3
- Atascosa, TX 78002 · last Feb 24, first Dec 2
- Pipe Creek, TX 78063 · last Mar 15, first Nov 13
Frequently asked questions
- When is the last frost in Rio Medina, TX?
- For ZIP code 78066, the average last spring frost (32°F) is February 28, based on NOAA 1991-2020 climate normals for the Hondo, TX weather station. There is a 1-in-10 chance of a frost after March 17.
- When is the first frost in Rio Medina, TX?
- The average first fall frost (32°F) is November 27. There is a 1-in-10 chance of frost by November 8, so tender plants are at risk from that point on.
- How long is the growing season in 78066?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 274 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.