Frost dates for 01267Williamstown, MA
The average last spring frost in Williamstown is May 10 and the average first fall frost is October 4, giving a typical growing season of about 147 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 4
- Growing season
- 147 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 21 (1-in-10 risk)
Last frost typically in 190 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) | May 7 · May 22 · Jun 5 | Sep 12 · Sep 25 · Oct 7 | 124 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 10 · May 25 | Sep 21 · Oct 4 · Oct 19 | 147 days | 100% |
| Hard freeze (28°F) | Apr 14 · Apr 30 · May 15 | Oct 2 · Oct 17 · Nov 3 | 170 days | 100% |
Planting calendar for Williamstown
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 | Apr 9 – Jun 15 |
| Tomatoes | Transplant outdoors | May 26 – Jun 14 |
| Peppers | Start seeds indoors | Apr 9 – May 10 |
| Peppers | Transplant outdoors | Jun 9 – Jul 10 |
| Eggplant | Start seeds indoors | Apr 26 – May 25 |
| Eggplant | Transplant outdoors | Jun 9 – Jul 10 |
| Cucumbers | Sow outdoors | Jun 9 – Jun 24 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 17 |
| Sweet corn | Sow outdoors | May 26 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 9 – Jul 10 |
| Okra | Sow outdoors | Jun 2 – Jun 25 |
| Peas | Sow outdoors (spring) | Apr 9 – May 25 |
| Potatoes | Plant outdoors (spring) | Apr 9 – Jun 9 |
| Onions | Start seeds indoors (spring) | Feb 26 – Mar 25 |
| Onions | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (spring) | Mar 22 – Apr 25 |
| Broccoli | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 01267 is matched to the NOAA station North Adams Harriman Ap, MA, 3.1 km away, at 654 ft elevation (2 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| North Adams Harriman Ap, MA (used) | 654 ft | May 10 | Oct 4 |
| Pownal 1 Ne, VT | 1,110 ft | May 7 | Oct 8 |
| Bennington Morse St Ap, VT | 826 ft | May 11 | Oct 2 |
| Grafton, NY | 1,560 ft | May 1 | Oct 11 |
Frost dates near Williamstown
- Pownal, VT 05261 · last May 7, first Oct 8
- North Adams, MA 01247 · last May 7, first Oct 8
- North Pownal, VT 05260 · last May 11, first Oct 2
- Adams, MA 01220 · last May 10, first Oct 4
- Petersburg, NY 12138 · last May 10, first Oct 4
- Stamford, VT 05352 · last May 7, first Oct 8
- Berlin, NY 12022 · last May 10, first Oct 4
- Cherry Plain, NY 12040 · last May 1, first Oct 11
Frequently asked questions
- When is the last frost in Williamstown, MA?
- For ZIP code 01267, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the North Adams Harriman Ap, MA weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Williamstown, MA?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 21, so tender plants are at risk from that point on.
- How long is the growing season in 01267?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 147 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.