Frost dates for 01741Carlisle, MA
The average last spring frost in Carlisle is April 27 and the average first fall frost is October 13, giving a typical growing season of about 169 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 27
- Average first fall frost
- Oct 13
- Growing season
- 169 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 1 (1-in-10 risk)
Last frost typically in 177 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 28 · May 9 · May 22 | Sep 20 · Oct 3 · Oct 16 | 146 days | 100% |
| Frost / freeze (32°F) | Apr 13 · Apr 27 · May 11 | Oct 1 · Oct 13 · Oct 29 | 169 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 12 · Apr 26 | Oct 9 · Oct 27 · Nov 10 | 197 days | 100% |
Planting calendar for Carlisle
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 27 – Jun 2 |
| Tomatoes | Transplant outdoors | May 13 – Jun 23 |
| Peppers | Start seeds indoors | Mar 27 – Apr 27 |
| Peppers | Transplant outdoors | May 27 – Jun 27 |
| Eggplant | Start seeds indoors | Apr 13 – May 12 |
| Eggplant | Transplant outdoors | May 27 – Jun 27 |
| Cucumbers | Sow outdoors | May 27 – Jul 3 |
| Summer squash | Sow outdoors | May 13 – Jun 27 |
| Winter squash & pumpkins | Sow outdoors | May 27 – Jun 27 |
| Snap beans | Sow outdoors | May 13 – Jul 26 |
| Sweet corn | Sow outdoors | May 13 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | May 27 – Jun 27 |
| Okra | Sow outdoors | May 20 – Jun 12 |
| Peas | Sow outdoors (spring) | Mar 27 – May 12 |
| Potatoes | Plant outdoors (spring) | Mar 27 – May 27 |
| Onions | Start seeds indoors (spring) | Feb 13 – Mar 12 |
| Onions | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (spring) | Mar 9 – Apr 12 |
| Broccoli | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Feb 27 – Mar 27 |
| Cabbage | Transplant outdoors (spring) | Mar 27 – Apr 27 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 27 – Jun 12 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 20 – May 3 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 27 – May 17 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 13 – May 3 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 01741 is matched to the NOAA station Bedford, MA, 7.5 km away, at 160 ft elevation (40 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Bedford, MA (used) | 160 ft | Apr 27 | Oct 13 |
| Bedford Hanscom Fld, MA | 133 ft | Apr 28 | Oct 10 |
| Lowell, MA | 110 ft | Apr 30 | Oct 10 |
| Maynard 2, MA | 205 ft | May 2 | Oct 6 |
Frost dates near Carlisle
- Nutting Lake, MA 01865 · last Apr 27, first Oct 13
- Chelmsford, MA 01824 · last Apr 30, first Oct 10
- North Billerica, MA 01862 · last Apr 30, first Oct 10
- Billerica, MA 01822 · last Apr 27, first Oct 13
- Bedford, MA 01730 · last Apr 27, first Oct 13
- Acton, MA 01718 · last May 2, first Oct 6
- Concord, MA 01742 · last Apr 28, first Oct 10
- Westford, MA 01886 · last Apr 30, first Oct 10
Frequently asked questions
- When is the last frost in Carlisle, MA?
- For ZIP code 01741, the average last spring frost (32°F) is April 27, based on NOAA 1991-2020 climate normals for the Bedford, MA weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Carlisle, MA?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
- How long is the growing season in 01741?
- 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.