Frost dates for 02638Dennis, MA
The average last spring frost in Dennis is April 22 and the average first fall frost is October 28, giving a typical growing season of about 188 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 22
- Average first fall frost
- Oct 28
- Growing season
- 188 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 13 (1-in-10 risk)
Last frost typically in 172 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 22 · May 3 · May 16 | Oct 1 · Oct 14 · Oct 30 | 164 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 22 · May 5 | Oct 13 · Oct 28 · Nov 11 | 188 days | 100% |
| Hard freeze (28°F) | Mar 23 · Apr 7 · Apr 21 | Oct 25 · Nov 9 · Nov 24 | 216 days | 100% |
Planting calendar for Dennis
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 22 – May 28 |
| Tomatoes | Transplant outdoors | May 8 – Jul 8 |
| Peppers | Start seeds indoors | Mar 22 – Apr 22 |
| Peppers | Transplant outdoors | May 22 – Jun 22 |
| Eggplant | Start seeds indoors | Apr 8 – May 7 |
| Eggplant | Transplant outdoors | May 22 – Jun 22 |
| Cucumbers | Sow outdoors | May 22 – Jul 18 |
| Summer squash | Sow outdoors | May 8 – Jun 22 |
| Winter squash & pumpkins | Sow outdoors | May 22 – Jun 22 |
| Snap beans | Sow outdoors | May 8 – Aug 10 |
| Sweet corn | Sow outdoors | May 8 – Jul 8 |
| Watermelon & cantaloupe | Sow outdoors | May 22 – Jun 22 |
| Okra | Sow outdoors | May 15 – Jun 7 |
| Peas | Sow outdoors (spring) | Mar 22 – May 7 |
| Potatoes | Plant outdoors (spring) | Mar 22 – May 22 |
| Onions | Start seeds indoors (spring) | Feb 8 – Mar 7 |
| Onions | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (spring) | Mar 4 – Apr 7 |
| Broccoli | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (fall) | Jun 28 – Jul 8 |
| Broccoli | Transplant outdoors (fall) | Jul 28 – Aug 8 |
| Cabbage | Start seeds indoors (spring) | Feb 22 – Mar 22 |
| Cabbage | Transplant outdoors (spring) | Mar 22 – Apr 22 |
| Cabbage | Start seeds indoors (fall) | Jun 18 – Jul 18 |
| Cabbage | Transplant outdoors (fall) | Jul 18 – Aug 18 |
| Leaf lettuce | Sow outdoors (spring) | Mar 22 – Jun 7 |
| Leaf lettuce | Sow outdoors (fall) | Jul 18 – Sep 3 |
| Spinach | Sow outdoors (spring) | Mar 15 – Apr 28 |
| Spinach | Sow outdoors (fall) | Aug 4 – Sep 8 |
| Radishes | Sow outdoors (spring) | Mar 22 – May 12 |
| Radishes | Sow outdoors (fall) | Jul 18 – Sep 18 |
| Kale | Sow outdoors (spring) | Apr 8 – Apr 28 |
| Kale | Sow outdoors (fall) | Jul 11 – Aug 18 |
| Carrots | Sow outdoors (spring) | Apr 22 – Jun 7 |
| Carrots | Sow outdoors (fall) | Jun 18 – Aug 3 |
| Garlic | Plant outdoors (fall) | Oct 18 – Nov 18 |
Where these dates come from
ZIP code 02638 is matched to the NOAA station Hyannis Barnstable Muni Ap, MA, 10.2 km away, at 55 ft elevation (43 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hyannis Barnstable Muni Ap, MA (used) | 55 ft | Apr 22 | Oct 28 |
| W Harwich, MA | 15 ft | Apr 13 | Nov 3 |
| Hyannis, MA | 60 ft | Apr 16 | Oct 30 |
| Chatham Muni Ap, MA | 68 ft | Apr 13 | Nov 4 |
Frost dates near Dennis
- East Dennis, MA 02641 · last Apr 22, first Oct 28
- South Dennis, MA 02660 · last Apr 22, first Oct 28
- Yarmouth Port, MA 02675 · last Apr 22, first Oct 28
- South Yarmouth, MA 02664 · last Apr 22, first Oct 28
- Cummaquid, MA 02637 · last Apr 22, first Oct 28
- West Dennis, MA 02670 · last Apr 22, first Oct 28
- West Yarmouth, MA 02673 · last Apr 22, first Oct 28
- Dennis Port, MA 02639 · last Apr 22, first Oct 28
Frequently asked questions
- When is the last frost in Dennis, MA?
- For ZIP code 02638, the average last spring frost (32°F) is April 22, based on NOAA 1991-2020 climate normals for the Hyannis Barnstable Muni Ap, MA weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Dennis, MA?
- The average first fall frost (32°F) is October 28. There is a 1-in-10 chance of frost by October 13, so tender plants are at risk from that point on.
- How long is the growing season in 02638?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 188 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.