Frost dates for 24520Alton, VA
The average last spring frost in Alton is April 10 and the average first fall frost is October 30, giving a typical growing season of about 202 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 10
- Average first fall frost
- Oct 30
- Growing season
- 202 days
Safer after Apr 30 (1-in-10 risk)
Possible by Oct 17 (1-in-10 risk)
Last frost typically in 158 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) | Apr 10 · Apr 23 · May 10 | Oct 9 · Oct 22 · Nov 2 | 180 days | 100% |
| Frost / freeze (32°F) | Mar 25 · Apr 10 · Apr 30 | Oct 17 · Oct 30 · Nov 12 | 202 days | 100% |
| Hard freeze (28°F) | Mar 12 · Mar 29 · Apr 13 | Oct 26 · Nov 7 · Nov 26 | 224 days | 100% |
Planting calendar for Alton
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 | Mar 10 – May 16 |
| Tomatoes | Transplant outdoors | Apr 26 – Jul 10 |
| Peppers | Start seeds indoors | Mar 10 – Apr 10 |
| Peppers | Transplant outdoors | May 10 – Jun 10 |
| Eggplant | Start seeds indoors | Mar 27 – Apr 25 |
| Eggplant | Transplant outdoors | May 10 – Jun 10 |
| Cucumbers | Sow outdoors | May 10 – Jul 20 |
| Summer squash | Sow outdoors | Apr 26 – Jun 10 |
| Winter squash & pumpkins | Sow outdoors | May 10 – Jun 10 |
| Snap beans | Sow outdoors | Apr 26 – Aug 12 |
| Sweet corn | Sow outdoors | Apr 26 – Jul 10 |
| Watermelon & cantaloupe | Sow outdoors | May 10 – Jun 10 |
| Okra | Sow outdoors | May 3 – May 26 |
| Peas | Sow outdoors (spring) | Mar 10 – Apr 25 |
| Potatoes | Plant outdoors (spring) | Mar 10 – May 10 |
| Onions | Start seeds indoors (spring) | Jan 27 – Feb 23 |
| Onions | Transplant outdoors (spring) | Mar 27 – Apr 25 |
| Broccoli | Start seeds indoors (spring) | Feb 20 – Mar 26 |
| Broccoli | Transplant outdoors (spring) | Mar 27 – Apr 25 |
| Broccoli | Start seeds indoors (fall) | Jun 30 – Jul 10 |
| Broccoli | Transplant outdoors (fall) | Jul 30 – Aug 10 |
| Cabbage | Start seeds indoors (spring) | Feb 10 – Mar 10 |
| Cabbage | Transplant outdoors (spring) | Mar 10 – Apr 10 |
| Cabbage | Start seeds indoors (fall) | Jun 20 – Jul 20 |
| Cabbage | Transplant outdoors (fall) | Jul 20 – Aug 20 |
| Leaf lettuce | Sow outdoors (spring) | Mar 10 – May 26 |
| Leaf lettuce | Sow outdoors (fall) | Jul 20 – Sep 5 |
| Spinach | Sow outdoors (spring) | Mar 3 – Apr 16 |
| Spinach | Sow outdoors (fall) | Aug 6 – Sep 10 |
| Radishes | Sow outdoors (spring) | Mar 10 – Apr 30 |
| Radishes | Sow outdoors (fall) | Jul 20 – Sep 20 |
| Kale | Sow outdoors (spring) | Mar 27 – Apr 16 |
| Kale | Sow outdoors (fall) | Jul 13 – Aug 20 |
| Carrots | Sow outdoors (spring) | Apr 10 – May 26 |
| Carrots | Sow outdoors (fall) | Jun 20 – Aug 5 |
| Garlic | Plant outdoors (fall) | Oct 20 – Nov 20 |
Where these dates come from
ZIP code 24520 is matched to the NOAA station S Boston, VA, 17.1 km away, at 329 ft elevation (153 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| S Boston, VA (used) | 329 ft | Apr 10 | Oct 30 |
| Danville Rgnl Ap, VA | 571 ft | Apr 10 | Oct 28 |
| Roxboro 7 Ese, NC | 710 ft | Apr 15 | Oct 26 |
| Danville 2 Se, VA | 392 ft | Apr 8 | Nov 1 |
Frost dates near Alton
- Cluster Springs, VA 24535 · last Apr 10, first Oct 30
- Semora, NC 27343 · last Apr 8, first Nov 1
- South Boston, VA 24592 · last Apr 10, first Oct 30
- Sutherlin, VA 24594 · last Apr 8, first Nov 1
- Milton, NC 27305 · last Apr 8, first Nov 1
- Halifax, VA 24558 · last Apr 10, first Oct 30
- Roxboro, NC 27573 · last Apr 15, first Oct 26
- Vernon Hill, VA 24597 · last Apr 10, first Oct 30
Frequently asked questions
- When is the last frost in Alton, VA?
- For ZIP code 24520, the average last spring frost (32°F) is April 10, based on NOAA 1991-2020 climate normals for the S Boston, VA weather station. There is a 1-in-10 chance of a frost after April 30.
- When is the first frost in Alton, VA?
- The average first fall frost (32°F) is October 30. There is a 1-in-10 chance of frost by October 17, so tender plants are at risk from that point on.
- How long is the growing season in 24520?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 202 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.