Old Lyme, CT frost dates
Last spring frostApr 16median date
First fall frostOct 28median date
Growing season195 daysfrost-free
Hardiness zone7aZone 7a
How Old Lyme compares
- In 8 years out of 10, the last spring frost in Old Lyme falls between April 3 and April 30, a 27-day window. The first fall frost falls between October 13 and November 12.
- The median last frost is 5 days earlier than the Connecticut median of Apr 21.
- Its 195-day growing season is longer than 88% of the 267 Connecticut places with a regular frost season (state median 178 days).
- The last frost is typical for zone 7a, where the median is Apr 16.
- The weather station records an average of 107 nights a year at or below 32°F.
- Compared with Meriden, CT, 47 km away, the last frost here is 10 days earlier than there and the growing season is 22 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 3 |
| 50% (median) | April 16 |
| 10% (safe for tender plants) | April 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 13 |
| 50% (median) | October 28 |
| 90% (late) | November 12 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Old Lyme, CT
Old Lyme, CT frost dates — last frost Apr 16, first frost Oct 28, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 22 to Feb 5Transplant outside: Mar 19 to Apr 2
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 23 to May 7
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Sow outdoors: Mar 19 to Apr 23Plant for fall: Sep 2 to Sep 30
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 19 to Apr 2Sow outdoors: Mar 19 to Apr 2Plant for fall: Aug 19 to Sep 9
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 22 to Aug 12
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Plant for fall: Jul 22 to Aug 12
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 22 to Aug 12
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21Sow outdoors: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 23 to May 7
Sow outdoors: Mar 5 to Mar 26Plant for fall: Aug 5 to Aug 26
Sow outdoors: Mar 5 to Mar 26Plant for fall: Sep 2 to Sep 23
Sow outdoors: Mar 12 to Apr 23Plant for fall: Sep 16 to Oct 7
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 7Sow outdoors: Apr 23 to May 7Plant for fall: Aug 12 to Aug 26
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7Plant for fall: Aug 19 to Sep 2
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 14
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 5 to Aug 19
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 19 to Sep 2
Sow outdoors: Mar 26 to Apr 16
Sow outdoors: Apr 2 to Apr 30Plant for fall: Aug 19 to Sep 2
Sow outdoors: Apr 2 to Apr 23Plant for fall: Sep 2 to Sep 23
Sow outdoors: Apr 23 to May 14Plant for fall: Aug 12 to Aug 26
Sow outdoors: Apr 23 to May 7
Transplant outside: Apr 30 to May 21
Plant for fall: Oct 14 to Nov 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Old Lyme, CT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 22 – Feb 5 | Mar 19 – Apr 2 | — | — |
| Peppers | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Eggplant | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Tomatoes | Feb 19 – Mar 5 | Apr 23 – May 7 | — | — |
| Lettuce | Feb 19 – Mar 5 | Mar 26 – Apr 9 | Mar 19 – Apr 23 | Sep 2 – Sep 30 |
| Kale | Feb 19 – Mar 5 | Mar 19 – Apr 2 | Mar 19 – Apr 2 | Aug 19 – Sep 9 |
| Broccoli | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 22 – Aug 12 |
| Cabbage | Feb 19 – Mar 5 | Mar 26 – Apr 9 | — | Jul 22 – Aug 12 |
| Cauliflower | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 22 – Aug 12 |
| Okra | Mar 5 – Mar 19 | May 7 – May 21 | May 7 – May 21 | — |
| Basil | Mar 5 – Mar 19 | Apr 23 – May 7 | — | — |
| Peas | — | — | Mar 5 – Mar 26 | Aug 5 – Aug 26 |
| Spinach | — | — | Mar 5 – Mar 26 | Sep 2 – Sep 23 |
| Radishes | — | — | Mar 12 – Apr 23 | Sep 16 – Oct 7 |
| Cucumbers | Mar 19 – Mar 26 | Apr 30 – May 7 | Apr 23 – May 7 | Aug 12 – Aug 26 |
| Zucchini & Summer Squash | Mar 19 – Mar 26 | — | Apr 23 – May 7 | Aug 19 – Sep 2 |
| Winter Squash & Pumpkins | Mar 19 – Mar 26 | — | Apr 23 – May 7 | — |
| Melons & Watermelon | Mar 19 – Mar 26 | Apr 30 – May 14 | — | — |
| Carrots | — | — | Mar 26 – Apr 23 | Aug 5 – Aug 19 |
| Beets | — | — | Mar 26 – Apr 23 | Aug 19 – Sep 2 |
| Potatoes | — | — | Mar 26 – Apr 16 | — |
| Swiss Chard | — | — | Apr 2 – Apr 30 | Aug 19 – Sep 2 |
| Cilantro | — | — | Apr 2 – Apr 23 | Sep 2 – Sep 23 |
| Green Beans | — | — | Apr 23 – May 14 | Aug 12 – Aug 26 |
| Sweet Corn | — | — | Apr 23 – May 7 | — |
| Sweet Potatoes | — | Apr 30 – May 21 | — | — |
| Garlic | — | — | — | Oct 14 – Nov 18 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Groton New London Ap, CT weather station, 22 km away (elevation 10 ft (3 m)).
Frost dates near Old Lyme
- South Lyme Apr 16 · Oct 28
- East Lyme Apr 16 · Oct 28
- Essex Apr 6 · Nov 17
- Old Saybrook Apr 6 · Nov 17
- Niantic Apr 16 · Oct 28
- Centerbrook Apr 6 · Nov 17
- Ivoryton Apr 6 · Nov 17
- Deep River Apr 6 · Nov 17
- Hadlyme Apr 14 · Oct 24
- Westbrook Apr 6 · Nov 17
Frequently asked questions
When is the last frost in Old Lyme, CT?
The median last spring frost in Old Lyme, CT is April 16. There is still about a 10% chance of frost after April 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Old Lyme, CT?
The median first fall frost is October 28, with about a 10% chance of frost before October 13.
How long is the growing season in Old Lyme, CT?
About 195 days between the median last spring frost and first fall frost.
What planting zone is Old Lyme, CT?
Old Lyme, CT is in USDA hardiness zone 7a.