Frost dates for 05495Williston, VT
The average last spring frost in Williston is April 29 and the average first fall frost is October 15, giving a typical growing season of about 169 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 15
- Growing season
- 169 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 179 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 27 · May 8 · May 23 | Sep 23 · Oct 4 · Oct 19 | 147 days | 100% |
| Frost / freeze (32°F) | Apr 17 · Apr 29 · May 11 | Oct 2 · Oct 15 · Nov 1 | 169 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 18 · Apr 30 | Oct 12 · Oct 28 · Nov 12 | 193 days | 100% |
Planting calendar for Williston
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 25 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 5 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 28 |
| Sweet corn | Sow outdoors | May 15 – Jun 25 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 15 – Jun 25 |
| Broccoli | Transplant outdoors (fall) | Jul 15 – Jul 26 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 5 – Jul 5 |
| Cabbage | Transplant outdoors (fall) | Jul 5 – Aug 5 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 5 – Aug 21 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 22 – Aug 26 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 5 – Sep 5 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 28 – Aug 5 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 5 – Jul 21 |
| Garlic | Plant outdoors (fall) | Oct 5 – Nov 5 |
Where these dates come from
ZIP code 05495 is matched to the NOAA station Burlington Intl Ap, VT, 5.6 km away, at 330 ft elevation (182 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Burlington Intl Ap, VT (used) | 330 ft | Apr 29 | Oct 15 |
| Essex Junction 1 N, VT | 340 ft | May 2 | Oct 11 |
| Willsboro 1 N, NY | 180 ft | May 2 | Oct 14 |
| Mt Mansfield, VT | 3,950 ft | May 23 | Sep 30 |
Frost dates near Williston
- Burlington, VT 05402 · last Apr 29, first Oct 15
- South Burlington, VT 05407 · last Apr 29, first Oct 15
- Essex Junction, VT 05453 · last Apr 29, first Oct 15
- Colchester, VT 05439 · last Apr 29, first Oct 15
- Essex, VT 05451 · last May 2, first Oct 11
- Winooski, VT 05404 · last Apr 29, first Oct 15
- Shelburne, VT 05482 · last May 2, first Oct 14
- Hinesburg, VT 05461 · last Apr 29, first Oct 15
Frequently asked questions
- When is the last frost in Williston, VT?
- For ZIP code 05495, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Burlington Intl Ap, VT weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Williston, VT?
- The average first fall frost (32°F) is October 15. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 05495?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 169 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.