Frost dates for 01430Ashburnham, MA
The average last spring frost in Ashburnham is May 5 and the average first fall frost is October 7, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 7
- Growing season
- 152 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 186 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 4 · May 18 · May 31 | Sep 15 · Sep 28 · Oct 8 | 131 days | 100% |
| Frost / freeze (32°F) | Apr 25 · May 5 · May 19 | Sep 24 · Oct 7 · Oct 20 | 152 days | 100% |
| Hard freeze (28°F) | Apr 11 · Apr 25 · May 7 | Oct 3 · Oct 18 · Nov 3 | 175 days | 100% |
Planting calendar for Ashburnham
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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 17 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 27 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 20 |
| Sweet corn | Sow outdoors | May 21 – Jun 17 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 7 – Jun 17 |
| Broccoli | Transplant outdoors (fall) | Jul 7 – Jul 18 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 28 – Jun 27 |
| Cabbage | Transplant outdoors (fall) | Jun 27 – Jul 28 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 27 – Aug 13 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 14 – Aug 18 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 27 – Aug 28 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 20 – Jul 28 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 28 – Jul 13 |
| Garlic | Plant outdoors (fall) | Sep 27 – Oct 28 |
Where these dates come from
ZIP code 01430 is matched to the NOAA station Ashburnham N, MA, 1.5 km away, at 1,146 ft elevation (22 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ashburnham N, MA (used) | 1,146 ft | May 5 | Oct 7 |
| Ashburnham, MA | 1,108 ft | May 2 | Oct 13 |
| Fitchburg Coop, MA | 665 ft | May 1 | Oct 9 |
| Birch Hill Dam, MA | 855 ft | May 6 | Oct 1 |
Frost dates near Ashburnham
- Ashby, MA 01431 · last May 10, first Oct 6
- Gardner, MA 01440 · last May 2, first Oct 13
- Winchendon, MA 01475 · last May 6, first Oct 1
- Westminster, MA 01473 · last May 12, first Oct 1
- New Ipswich, NH 03071 · last May 5, first Oct 6
- Fitchburg, MA 01420 · last Apr 29, first Oct 11
- Baldwinville, MA 01436 · last May 6, first Oct 1
- East Templeton, MA 01438 · last May 6, first Oct 1
Frequently asked questions
- When is the last frost in Ashburnham, MA?
- For ZIP code 01430, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Ashburnham N, MA weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Ashburnham, MA?
- The average first fall frost (32°F) is October 7. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 01430?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 152 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.