Frost dates for 06339Ledyard, CT
The average last spring frost in Ledyard is April 8 and the average first fall frost is November 2, giving a typical growing season of about 207 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 8
- Average first fall frost
- Nov 2
- Growing season
- 207 days
Safer after Apr 22 (1-in-10 risk)
Possible by Oct 18 (1-in-10 risk)
First frost typically in 2 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 10 · Apr 22 · May 5 | Oct 8 · Oct 21 · Nov 4 | 181 days | 100% |
| Frost / freeze (32°F) | Mar 28 · Apr 8 · Apr 22 | Oct 18 · Nov 2 · Nov 15 | 207 days | 100% |
| Hard freeze (28°F) | Mar 14 · Mar 29 · Apr 7 | Nov 1 · Nov 14 · Dec 1 | 232 days | 100% |
Planting calendar for Ledyard
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 8 – May 14 |
| Tomatoes | Transplant outdoors | Apr 24 – Jul 13 |
| Peppers | Start seeds indoors | Mar 8 – Apr 8 |
| Peppers | Transplant outdoors | May 8 – Jun 8 |
| Eggplant | Start seeds indoors | Mar 25 – Apr 23 |
| Eggplant | Transplant outdoors | May 8 – Jun 8 |
| Cucumbers | Sow outdoors | May 8 – Jul 23 |
| Summer squash | Sow outdoors | Apr 24 – Jun 8 |
| Winter squash & pumpkins | Sow outdoors | May 8 – Jun 8 |
| Snap beans | Sow outdoors | Apr 24 – Aug 15 |
| Sweet corn | Sow outdoors | Apr 24 – Jul 13 |
| Watermelon & cantaloupe | Sow outdoors | May 8 – Jun 8 |
| Okra | Sow outdoors | May 1 – May 24 |
| Peas | Sow outdoors (spring) | Mar 8 – Apr 23 |
| Potatoes | Plant outdoors (spring) | Mar 8 – May 8 |
| Onions | Start seeds indoors (spring) | Jan 25 – Feb 21 |
| Onions | Transplant outdoors (spring) | Mar 25 – Apr 23 |
| Broccoli | Start seeds indoors (spring) | Feb 18 – Mar 24 |
| Broccoli | Transplant outdoors (spring) | Mar 25 – Apr 23 |
| Broccoli | Start seeds indoors (fall) | Jul 3 – Jul 13 |
| Broccoli | Transplant outdoors (fall) | Aug 2 – Aug 13 |
| Cabbage | Start seeds indoors (spring) | Feb 8 – Mar 8 |
| Cabbage | Transplant outdoors (spring) | Mar 8 – Apr 8 |
| Cabbage | Start seeds indoors (fall) | Jun 23 – Jul 23 |
| Cabbage | Transplant outdoors (fall) | Jul 23 – Aug 23 |
| Leaf lettuce | Sow outdoors (spring) | Mar 8 – May 24 |
| Leaf lettuce | Sow outdoors (fall) | Jul 23 – Sep 8 |
| Spinach | Sow outdoors (spring) | Mar 1 – Apr 14 |
| Spinach | Sow outdoors (fall) | Aug 9 – Sep 13 |
| Radishes | Sow outdoors (spring) | Mar 8 – Apr 28 |
| Radishes | Sow outdoors (fall) | Jul 23 – Sep 23 |
| Kale | Sow outdoors (spring) | Mar 25 – Apr 14 |
| Kale | Sow outdoors (fall) | Jul 16 – Aug 23 |
| Carrots | Sow outdoors (spring) | Apr 8 – May 24 |
| Carrots | Sow outdoors (fall) | Jun 23 – Aug 8 |
| Garlic | Plant outdoors (fall) | Oct 23 – Nov 23 |
Where these dates come from
ZIP code 06339 is matched to the NOAA station Groton, CT, 10.6 km away, at 40 ft elevation (242 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Groton, CT (used) | 40 ft | Apr 8 | Nov 2 |
| Norwich Public Utility Plt, CT | 20 ft | Apr 14 | Oct 24 |
| Groton New London Ap, CT | 10 ft | Apr 16 | Oct 28 |
| Westerly State Ap, RI | 81 ft | Apr 11 | Oct 31 |
Frost dates near Ledyard
- Mashantucket, CT 06338 · last Apr 14, first Oct 24
- Gales Ferry, CT 06335 · last Apr 8, first Nov 2
- Old Mystic, CT 06372 · last Apr 8, first Nov 2
- Mystic, CT 06355 · last Apr 8, first Nov 2
- Groton, CT 06349 · last Apr 8, first Nov 2
- Preston, CT 06365 · last Apr 14, first Oct 24
- Uncasville, CT 06382 · last Apr 14, first Oct 24
- North Stonington, CT 06359 · last Apr 11, first Oct 31
Frequently asked questions
- When is the last frost in Ledyard, CT?
- For ZIP code 06339, the average last spring frost (32°F) is April 8, based on NOAA 1991-2020 climate normals for the Groton, CT weather station. There is a 1-in-10 chance of a frost after April 22.
- When is the first frost in Ledyard, CT?
- The average first fall frost (32°F) is November 2. There is a 1-in-10 chance of frost by October 18, so tender plants are at risk from that point on.
- How long is the growing season in 06339?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 207 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.