Frost dates for 01473Westminster, MA
The average last spring frost in Westminster is May 12 and the average first fall frost is October 1, giving a typical growing season of about 141 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Oct 1
- Growing season
- 141 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 192 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 10 · May 25 · Jun 7 | Sep 6 · Sep 22 · Oct 4 | 118 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 12 · May 28 | Sep 18 · Oct 1 · Oct 15 | 141 days | 100% |
| Hard freeze (28°F) | Apr 16 · Apr 29 · May 15 | Sep 30 · Oct 10 · Oct 29 | 165 days | 100% |
Planting calendar for Westminster
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 11 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 21 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 14 |
| Sweet corn | Sow outdoors | May 28 – Jun 11 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 01473 is matched to the NOAA station Barre Falls Dam, MA, 16.5 km away, at 825 ft elevation (182 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Barre Falls Dam, MA (used) | 825 ft | May 12 | Oct 1 |
| Ashburnham, MA | 1,108 ft | May 2 | Oct 13 |
| Fitchburg Coop, MA | 665 ft | May 1 | Oct 9 |
| Fitchburg Muni Ap, MA | 348 ft | Apr 29 | Oct 11 |
Frost dates near Westminster
- Westminster, MA 01441 · last May 2, first Oct 13
- Gardner, MA 01440 · last May 2, first Oct 13
- Fitchburg, MA 01420 · last Apr 29, first Oct 11
- Hubbardston, MA 01452 · last May 12, first Oct 1
- East Templeton, MA 01438 · last May 6, first Oct 1
- Princeton, MA 01541 · last Apr 23, first Oct 21
- Ashburnham, MA 01430 · last May 5, first Oct 7
- Templeton, MA 01468 · last May 6, first Oct 1
Frequently asked questions
- When is the last frost in Westminster, MA?
- For ZIP code 01473, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Barre Falls Dam, MA weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Westminster, MA?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 01473?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 141 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.