Mystic, CT frost dates
Last spring frostApr 8median date
First fall frostNov 2median date
Growing season208 daysfrost-free
Hardiness zone7aZone 7a
How Mystic compares
- In 8 years out of 10, the last spring frost in Mystic falls between March 28 and April 22, a 25-day window. The first fall frost falls between October 18 and November 15.
- The median last frost is 13 days earlier than the Connecticut median of Apr 21.
- Its 208-day growing season is longer than 92% of the 267 Connecticut places with a regular frost season (state median 178 days).
- The last frost is 8 days earlier than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 102 nights a year at or below 32°F.
- Compared with Warwick, RI, 61 km away, the last frost here is 3 days earlier than there and the growing season is 6 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 28 |
| 50% (median) | April 8 |
| 10% (safe for tender plants) | April 22 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 18 |
| 50% (median) | November 2 |
| 90% (late) | November 15 |
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 Mystic, CT
Mystic, CT frost dates — last frost Apr 8, first frost Nov 2, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 14 to Jan 28Transplant outside: Mar 11 to Mar 25
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Feb 11 to Feb 25Transplant outside: Apr 15 to Apr 29
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Sow outdoors: Mar 11 to Apr 15Plant for fall: Sep 7 to Oct 5
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 11 to Mar 25Sow outdoors: Mar 11 to Mar 25Plant for fall: Aug 24 to Sep 14
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13Sow outdoors: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 15 to Apr 29
Sow outdoors: Feb 25 to Mar 18Plant for fall: Aug 10 to Aug 31
Sow outdoors: Feb 25 to Mar 18Plant for fall: Sep 7 to Sep 28
Sow outdoors: Mar 4 to Apr 15Plant for fall: Sep 21 to Oct 12
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 17 to Aug 31
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 24 to Sep 7
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to May 6
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 24 to Sep 7
Sow outdoors: Mar 18 to Apr 8
Sow outdoors: Mar 25 to Apr 22Plant for fall: Aug 24 to Sep 7
Sow outdoors: Mar 25 to Apr 15Plant for fall: Sep 7 to Sep 28
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 17 to Aug 31
Sow outdoors: Apr 15 to Apr 29
Transplant outside: Apr 22 to May 13
Plant for fall: Oct 19 to Nov 23
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Mystic, CT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 14 – Jan 28 | Mar 11 – Mar 25 | — | — |
| Peppers | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Eggplant | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Tomatoes | Feb 11 – Feb 25 | Apr 15 – Apr 29 | — | — |
| Lettuce | Feb 11 – Feb 25 | Mar 18 – Apr 1 | Mar 11 – Apr 15 | Sep 7 – Oct 5 |
| Kale | Feb 11 – Feb 25 | Mar 11 – Mar 25 | Mar 11 – Mar 25 | Aug 24 – Sep 14 |
| Broccoli | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 27 – Aug 17 |
| Cabbage | Feb 11 – Feb 25 | Mar 18 – Apr 1 | — | Jul 27 – Aug 17 |
| Cauliflower | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 27 – Aug 17 |
| Okra | Feb 25 – Mar 11 | Apr 29 – May 13 | Apr 29 – May 13 | — |
| Basil | Feb 25 – Mar 11 | Apr 15 – Apr 29 | — | — |
| Peas | — | — | Feb 25 – Mar 18 | Aug 10 – Aug 31 |
| Spinach | — | — | Feb 25 – Mar 18 | Sep 7 – Sep 28 |
| Radishes | — | — | Mar 4 – Apr 15 | Sep 21 – Oct 12 |
| Cucumbers | Mar 11 – Mar 18 | Apr 22 – Apr 29 | Apr 15 – Apr 29 | Aug 17 – Aug 31 |
| Zucchini & Summer Squash | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | Aug 24 – Sep 7 |
| Winter Squash & Pumpkins | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | — |
| Melons & Watermelon | Mar 11 – Mar 18 | Apr 22 – May 6 | — | — |
| Carrots | — | — | Mar 18 – Apr 15 | Aug 10 – Aug 24 |
| Beets | — | — | Mar 18 – Apr 15 | Aug 24 – Sep 7 |
| Potatoes | — | — | Mar 18 – Apr 8 | — |
| Swiss Chard | — | — | Mar 25 – Apr 22 | Aug 24 – Sep 7 |
| Cilantro | — | — | Mar 25 – Apr 15 | Sep 7 – Sep 28 |
| Green Beans | — | — | Apr 15 – May 6 | Aug 17 – Aug 31 |
| Sweet Corn | — | — | Apr 15 – Apr 29 | — |
| Sweet Potatoes | — | Apr 22 – May 13 | — | — |
| Garlic | — | — | — | Oct 19 – Nov 23 |
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, CT weather station, 5 km away (elevation 39 ft (12 m)).
Frost dates near Mystic
- West Mystic Apr 8 · Nov 2
- Old Mystic Apr 8 · Nov 2
- Stonington Apr 11 · Oct 31
- Groton Apr 8 · Nov 2
- Ledyard Apr 8 · Nov 2
- Gales Ferry Apr 8 · Nov 2
- Pawcatuck Apr 11 · Oct 31
- New London Apr 16 · Oct 28
- Quaker Hill Apr 8 · Nov 2
- Mashantucket Apr 14 · Oct 24
Frequently asked questions
When is the last frost in Mystic, CT?
The median last spring frost in Mystic, CT is April 8. There is still about a 10% chance of frost after April 22, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mystic, CT?
The median first fall frost is November 2, with about a 10% chance of frost before October 18.
How long is the growing season in Mystic, CT?
About 208 days between the median last spring frost and first fall frost.
What planting zone is Mystic, CT?
Mystic, CT is in USDA hardiness zone 7a.