Frost dates for 78663Round Mountain, TX
The average last spring frost in Round Mountain is March 22 and the average first fall frost is November 9, giving a typical growing season of about 235 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 22
- Average first fall frost
- Nov 9
- Growing season
- 235 days
Safer after Apr 11 (1-in-10 risk)
Possible by Oct 25 (1-in-10 risk)
First frost typically in 13 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 4 · Apr 24 | Oct 17 · Nov 1 · Nov 16 | 210 days | 100% |
| Frost / freeze (32°F) | Feb 27 · Mar 22 · Apr 11 | Oct 25 · Nov 9 · Nov 30 | 235 days | 100% |
| Hard freeze (28°F) | Feb 11 · Mar 6 · Mar 28 | Nov 2 · Nov 22 · Dec 15 | 260 days | 100% |
Planting calendar for Round Mountain
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 19 – Apr 27 |
| Tomatoes | Transplant outdoors | Apr 7 – Jul 20 |
| Peppers | Start seeds indoors | Feb 19 – Mar 22 |
| Peppers | Transplant outdoors | Apr 21 – May 22 |
| Eggplant | Start seeds indoors | Mar 8 – Apr 6 |
| Eggplant | Transplant outdoors | Apr 21 – May 22 |
| Cucumbers | Sow outdoors | Apr 21 – Jul 30 |
| Summer squash | Sow outdoors | Apr 7 – May 22 |
| Winter squash & pumpkins | Sow outdoors | Apr 21 – May 22 |
| Snap beans | Sow outdoors | Apr 7 – Aug 22 |
| Sweet corn | Sow outdoors | Apr 7 – Jul 20 |
| Watermelon & cantaloupe | Sow outdoors | Apr 21 – May 22 |
| Okra | Sow outdoors | Apr 14 – May 7 |
| Peas | Sow outdoors (spring) | Feb 19 – Apr 6 |
| Potatoes | Plant outdoors (spring) | Feb 19 – Apr 21 |
| Onions | Start seeds indoors (spring) | Jan 8 – Feb 4 |
| Onions | Transplant outdoors (spring) | Mar 8 – Apr 6 |
| Broccoli | Start seeds indoors (spring) | Feb 1 – Mar 7 |
| Broccoli | Transplant outdoors (spring) | Mar 8 – Apr 6 |
| Broccoli | Start seeds indoors (fall) | Jul 10 – Jul 20 |
| Broccoli | Transplant outdoors (fall) | Aug 9 – Aug 20 |
| Cabbage | Start seeds indoors (spring) | Jan 22 – Feb 19 |
| Cabbage | Transplant outdoors (spring) | Feb 19 – Mar 22 |
| Cabbage | Start seeds indoors (fall) | Jun 30 – Jul 30 |
| Cabbage | Transplant outdoors (fall) | Jul 30 – Aug 30 |
| Leaf lettuce | Sow outdoors (spring) | Feb 19 – May 7 |
| Leaf lettuce | Sow outdoors (fall) | Jul 30 – Sep 15 |
| Spinach | Sow outdoors (spring) | Feb 12 – Mar 28 |
| Spinach | Sow outdoors (fall) | Aug 16 – Sep 20 |
| Radishes | Sow outdoors (spring) | Feb 19 – Apr 11 |
| Radishes | Sow outdoors (fall) | Jul 30 – Sep 30 |
| Kale | Sow outdoors (spring) | Mar 8 – Mar 28 |
| Kale | Sow outdoors (fall) | Jul 23 – Aug 30 |
| Carrots | Sow outdoors (spring) | Mar 22 – May 7 |
| Carrots | Sow outdoors (fall) | Jun 30 – Aug 15 |
| Garlic | Plant outdoors (fall) | Oct 30 – Nov 30 |
Where these dates come from
ZIP code 78663 is matched to the NOAA station Johnson City 2N, TX, 16.1 km away, at 1,137 ft elevation (356 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Johnson City 2N, TX (used) | 1,137 ft | Mar 22 | Nov 9 |
| Burnet Muni Ap, TX | 1,288 ft | Mar 6 | Nov 23 |
| Blanco, TX | 1,310 ft | Mar 20 | Nov 10 |
| Austin 33 Nw, TX | 1,361 ft | Mar 2 | Nov 29 |
Frost dates near Round Mountain
- Horseshoe Bay, TX 78657 · last Mar 22, first Nov 9
- Johnson City, TX 78636 · last Mar 22, first Nov 9
- Marble Falls, TX 78654 · last Mar 6, first Nov 23
- Willow City, TX 78675 · last Mar 22, first Nov 9
- Kingsland, TX 78639 · last Mar 20, first Nov 10
- Hye, TX 78635 · last Mar 20, first Nov 10
- Stonewall, TX 78671 · last Mar 18, first Nov 10
- Llano, TX 78643 · last Mar 20, first Nov 10
Frequently asked questions
- When is the last frost in Round Mountain, TX?
- For ZIP code 78663, the average last spring frost (32°F) is March 22, based on NOAA 1991-2020 climate normals for the Johnson City 2N, TX weather station. There is a 1-in-10 chance of a frost after April 11.
- When is the first frost in Round Mountain, TX?
- The average first fall frost (32°F) is November 9. There is a 1-in-10 chance of frost by October 25, so tender plants are at risk from that point on.
- How long is the growing season in 78663?
- 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.