Frost dates for 06096Windsor Locks, CT
The average last spring frost in Windsor Locks is April 21 and the average first fall frost is October 16, giving a typical growing season of about 177 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 21
- Average first fall frost
- Oct 16
- Growing season
- 177 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 3 (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 5 · May 18 | Sep 26 · Oct 6 · Oct 21 | 153 days | 100% |
| Frost / freeze (32°F) | Apr 8 · Apr 21 · May 6 | Oct 3 · Oct 16 · Nov 2 | 177 days | 100% |
| Hard freeze (28°F) | Mar 26 · Apr 7 · Apr 22 | Oct 13 · Oct 29 · Nov 12 | 204 days | 100% |
Planting calendar for Windsor Locks
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 21 – May 27 |
| Tomatoes | Transplant outdoors | May 7 – Jun 26 |
| Peppers | Start seeds indoors | Mar 21 – Apr 21 |
| Peppers | Transplant outdoors | May 21 – Jun 21 |
| Eggplant | Start seeds indoors | Apr 7 – May 6 |
| Eggplant | Transplant outdoors | May 21 – Jun 21 |
| Cucumbers | Sow outdoors | May 21 – Jul 6 |
| Summer squash | Sow outdoors | May 7 – Jun 21 |
| Winter squash & pumpkins | Sow outdoors | May 21 – Jun 21 |
| Snap beans | Sow outdoors | May 7 – Jul 29 |
| Sweet corn | Sow outdoors | May 7 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | May 21 – Jun 21 |
| Okra | Sow outdoors | May 14 – Jun 6 |
| Peas | Sow outdoors (spring) | Mar 21 – May 6 |
| Potatoes | Plant outdoors (spring) | Mar 21 – May 21 |
| Onions | Start seeds indoors (spring) | Feb 7 – Mar 6 |
| Onions | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (spring) | Mar 3 – Apr 6 |
| Broccoli | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Feb 21 – Mar 21 |
| Cabbage | Transplant outdoors (spring) | Mar 21 – Apr 21 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Mar 21 – Jun 6 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Mar 14 – Apr 27 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Mar 21 – May 11 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | Apr 7 – Apr 27 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | Apr 21 – Jun 6 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 06096 is matched to the NOAA station Hartford Bradley Intl Ap, CT, 3.3 km away, at 190 ft elevation (55 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hartford Bradley Intl Ap, CT (used) | 190 ft | Apr 21 | Oct 16 |
| Hartford Brainard Fld, CT | 19 ft | Apr 17 | Oct 26 |
| Westfield 3 Sw, MA | 430 ft | Apr 28 | Oct 17 |
| Barkhamsted, CT | 710 ft | Apr 30 | Oct 17 |
Frost dates near Windsor Locks
- Hartford, CT 06199 · last Apr 21, first Oct 16
- Poquonock, CT 06064 · last Apr 21, first Oct 16
- East Windsor, CT 06088 · last Apr 21, first Oct 16
- Suffield, CT 06080 · last Apr 21, first Oct 16
- Enfield, CT 06083 · last Apr 21, first Oct 16
- Windsor, CT 06095 · last Apr 21, first Oct 16
- East Windsor Hill, CT 06028 · last Apr 21, first Oct 16
- East Granby, CT 06026 · last Apr 21, first Oct 16
Frequently asked questions
- When is the last frost in Windsor Locks, CT?
- For ZIP code 06096, the average last spring frost (32°F) is April 21, based on NOAA 1991-2020 climate normals for the Hartford Bradley Intl Ap, CT weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Windsor Locks, CT?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by October 3, so tender plants are at risk from that point on.
- How long is the growing season in 06096?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 177 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.