Colebrook, CT frost dates
Last spring frostMay 3median date
First fall frostOct 11median date
Growing season161 daysfrost-free
Hardiness zone6aZone 6a
How Colebrook compares
- In 8 years out of 10, the last spring frost in Colebrook falls between April 21 and May 17, a 26-day window. The first fall frost falls between October 1 and October 28.
- The median last frost is 12 days later than the Connecticut median of Apr 21.
- Its 161-day growing season is longer than 10% of the 267 Connecticut places with a regular frost season (state median 178 days).
- The last frost is 4 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 152 nights a year at or below 32°F.
- Compared with Bristol, CT, 37 km away, the last frost here is 8 days later than there and the growing season is 15 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 21 |
| 50% (median) | May 3 |
| 10% (safe for tender plants) | May 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 11 |
| 90% (late) | October 28 |
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 Colebrook, CT
Colebrook, CT frost dates — last frost May 3, first frost Oct 11, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 8 to Feb 22Transplant outside: Apr 5 to Apr 19
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Mar 8 to Mar 22Transplant outside: May 10 to May 24
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Sow outdoors: Apr 5 to May 10Plant for fall: Aug 16 to Sep 13
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 5 to Apr 19Sow outdoors: Apr 5 to Apr 19Plant for fall: Aug 2 to Aug 23
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jul 5 to Jul 26
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Plant for fall: Jul 5 to Jul 26
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jul 5 to Jul 26
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7Sow outdoors: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: May 10 to May 24
Sow outdoors: Mar 22 to Apr 12Plant for fall: Jul 19 to Aug 9
Sow outdoors: Mar 22 to Apr 12Plant for fall: Aug 16 to Sep 6
Sow outdoors: Mar 29 to May 10Plant for fall: Aug 30 to Sep 20
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 24Sow outdoors: May 10 to May 24Plant for fall: Jul 26 to Aug 9
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24Plant for fall: Aug 2 to Aug 16
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 31
Sow outdoors: Apr 12 to May 10Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 12 to May 10Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 12 to May 3
Sow outdoors: Apr 19 to May 17Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 19 to May 10Plant for fall: Aug 16 to Sep 6
Sow outdoors: May 10 to May 31Plant for fall: Jul 26 to Aug 9
Sow outdoors: May 10 to May 24
Transplant outside: May 17 to Jun 7
Plant for fall: Sep 27 to Nov 1
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Colebrook, CT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Peppers | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Tomatoes | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Lettuce | Mar 8 – Mar 22 | Apr 12 – Apr 26 | Apr 5 – May 10 | Aug 16 – Sep 13 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 19 | Apr 5 – Apr 19 | Aug 2 – Aug 23 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 5 – Jul 26 |
| Cabbage | Mar 8 – Mar 22 | Apr 12 – Apr 26 | — | Jul 5 – Jul 26 |
| Cauliflower | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 5 – Jul 26 |
| Okra | Mar 22 – Apr 5 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Basil | Mar 22 – Apr 5 | May 10 – May 24 | — | — |
| Peas | — | — | Mar 22 – Apr 12 | Jul 19 – Aug 9 |
| Spinach | — | — | Mar 22 – Apr 12 | Aug 16 – Sep 6 |
| Radishes | — | — | Mar 29 – May 10 | Aug 30 – Sep 20 |
| Cucumbers | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 24 | Jul 26 – Aug 9 |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | — | May 10 – May 24 | Aug 2 – Aug 16 |
| Winter Squash & Pumpkins | Apr 5 – Apr 12 | — | May 10 – May 24 | — |
| Melons & Watermelon | Apr 5 – Apr 12 | May 17 – May 31 | — | — |
| Carrots | — | — | Apr 12 – May 10 | Jul 19 – Aug 2 |
| Beets | — | — | Apr 12 – May 10 | Aug 2 – Aug 16 |
| Potatoes | — | — | Apr 12 – May 3 | — |
| Swiss Chard | — | — | Apr 19 – May 17 | Aug 2 – Aug 16 |
| Cilantro | — | — | Apr 19 – May 10 | Aug 16 – Sep 6 |
| Green Beans | — | — | May 10 – May 31 | Jul 26 – Aug 9 |
| Sweet Corn | — | — | May 10 – May 24 | — |
| Sweet Potatoes | — | May 17 – Jun 7 | — | — |
| Garlic | — | — | — | Sep 27 – Nov 1 |
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 Norfolk 2 Sw, CT weather station, 10 km away (elevation 1,339 ft (408 m)).
Frost dates near Colebrook
- Riverton Apr 30 · Oct 17
- Winsted Apr 30 · Oct 17
- Norfolk May 3 · Oct 11
- West Hartland Apr 30 · Oct 17
- Winchester Center May 3 · Oct 11
- East Hartland Apr 30 · Oct 17
- East Canaan May 3 · Oct 11
- Pine Meadow Apr 30 · Oct 17
- Barkhamsted Apr 30 · Oct 17
- New Hartford May 8 · Oct 5
Frequently asked questions
When is the last frost in Colebrook, CT?
The median last spring frost in Colebrook, CT is May 3. There is still about a 10% chance of frost after May 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Colebrook, CT?
The median first fall frost is October 11, with about a 10% chance of frost before October 1.
How long is the growing season in Colebrook, CT?
About 161 days between the median last spring frost and first fall frost.
What planting zone is Colebrook, CT?
Colebrook, CT is in USDA hardiness zone 6a.