Watertown, CT frost dates
Last spring frostApr 25median date
First fall frostOct 18median date
Growing season176 daysfrost-free
Hardiness zone6bZone 6b
How Watertown compares
- In 8 years out of 10, the last spring frost in Watertown falls between April 12 and May 10, a 28-day window. The first fall frost falls between October 4 and November 1.
- The median last frost is 4 days later than the Connecticut median of Apr 21.
- Its 176-day growing season is longer than 41% of the 267 Connecticut places with a regular frost season (state median 178 days).
- The last frost is typical for zone 6b, where the median is Apr 22.
- The weather station records an average of 142 nights a year at or below 32°F.
- Compared with Waterbury, CT, 8 km away, the last frost here is 1 day earlier than there and the growing season is 3 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 12 |
| 50% (median) | April 25 |
| 10% (safe for tender plants) | May 10 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 4 |
| 50% (median) | October 18 |
| 90% (late) | November 1 |
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 Watertown, CT
Watertown, CT frost dates — last frost Apr 25, first frost Oct 18, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 31 to Feb 14Transplant outside: Mar 28 to Apr 11
Start indoors: Feb 14 to Feb 28Transplant outside: May 9 to May 23
Start indoors: Feb 14 to Feb 28Transplant outside: May 9 to May 23
Start indoors: Feb 28 to Mar 14Transplant outside: May 2 to May 16
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 4 to Apr 18Sow outdoors: Mar 28 to May 2Plant for fall: Aug 23 to Sep 20
Start indoors: Feb 28 to Mar 14Transplant outside: Mar 28 to Apr 11Sow outdoors: Mar 28 to Apr 11Plant for fall: Aug 9 to Aug 30
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 11 to Apr 25Plant for fall: Jul 12 to Aug 2
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 4 to Apr 18Plant for fall: Jul 12 to Aug 2
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 11 to Apr 25Plant for fall: Jul 12 to Aug 2
Start indoors: Mar 14 to Mar 28Transplant outside: May 16 to May 30Sow outdoors: May 16 to May 30
Start indoors: Mar 14 to Mar 28Transplant outside: May 2 to May 16
Sow outdoors: Mar 14 to Apr 4Plant for fall: Jul 26 to Aug 16
Sow outdoors: Mar 14 to Apr 4Plant for fall: Aug 23 to Sep 13
Sow outdoors: Mar 21 to May 2Plant for fall: Sep 6 to Sep 27
Start indoors: Mar 28 to Apr 4Transplant outside: May 9 to May 16Sow outdoors: May 2 to May 16Plant for fall: Aug 2 to Aug 16
Start indoors: Mar 28 to Apr 4Sow outdoors: May 2 to May 16Plant for fall: Aug 9 to Aug 23
Start indoors: Mar 28 to Apr 4Sow outdoors: May 2 to May 16
Start indoors: Mar 28 to Apr 4Transplant outside: May 9 to May 23
Sow outdoors: Apr 4 to May 2Plant for fall: Jul 26 to Aug 9
Sow outdoors: Apr 4 to May 2Plant for fall: Aug 9 to Aug 23
Sow outdoors: Apr 4 to Apr 25
Sow outdoors: Apr 11 to May 9Plant for fall: Aug 9 to Aug 23
Sow outdoors: Apr 11 to May 2Plant for fall: Aug 23 to Sep 13
Sow outdoors: May 2 to May 23Plant for fall: Aug 2 to Aug 16
Sow outdoors: May 2 to May 16
Transplant outside: May 9 to May 30
Plant for fall: Oct 4 to Nov 8
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Watertown, CT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 31 – Feb 14 | Mar 28 – Apr 11 | — | — |
| Peppers | Feb 14 – Feb 28 | May 9 – May 23 | — | — |
| Eggplant | Feb 14 – Feb 28 | May 9 – May 23 | — | — |
| Tomatoes | Feb 28 – Mar 14 | May 2 – May 16 | — | — |
| Lettuce | Feb 28 – Mar 14 | Apr 4 – Apr 18 | Mar 28 – May 2 | Aug 23 – Sep 20 |
| Kale | Feb 28 – Mar 14 | Mar 28 – Apr 11 | Mar 28 – Apr 11 | Aug 9 – Aug 30 |
| Broccoli | Feb 28 – Mar 14 | Apr 11 – Apr 25 | — | Jul 12 – Aug 2 |
| Cabbage | Feb 28 – Mar 14 | Apr 4 – Apr 18 | — | Jul 12 – Aug 2 |
| Cauliflower | Feb 28 – Mar 14 | Apr 11 – Apr 25 | — | Jul 12 – Aug 2 |
| Okra | Mar 14 – Mar 28 | May 16 – May 30 | May 16 – May 30 | — |
| Basil | Mar 14 – Mar 28 | May 2 – May 16 | — | — |
| Peas | — | — | Mar 14 – Apr 4 | Jul 26 – Aug 16 |
| Spinach | — | — | Mar 14 – Apr 4 | Aug 23 – Sep 13 |
| Radishes | — | — | Mar 21 – May 2 | Sep 6 – Sep 27 |
| Cucumbers | Mar 28 – Apr 4 | May 9 – May 16 | May 2 – May 16 | Aug 2 – Aug 16 |
| Zucchini & Summer Squash | Mar 28 – Apr 4 | — | May 2 – May 16 | Aug 9 – Aug 23 |
| Winter Squash & Pumpkins | Mar 28 – Apr 4 | — | May 2 – May 16 | — |
| Melons & Watermelon | Mar 28 – Apr 4 | May 9 – May 23 | — | — |
| Carrots | — | — | Apr 4 – May 2 | Jul 26 – Aug 9 |
| Beets | — | — | Apr 4 – May 2 | Aug 9 – Aug 23 |
| Potatoes | — | — | Apr 4 – Apr 25 | — |
| Swiss Chard | — | — | Apr 11 – May 9 | Aug 9 – Aug 23 |
| Cilantro | — | — | Apr 11 – May 2 | Aug 23 – Sep 13 |
| Green Beans | — | — | May 2 – May 23 | Aug 2 – Aug 16 |
| Sweet Corn | — | — | May 2 – May 16 | — |
| Sweet Potatoes | — | May 9 – May 30 | — | — |
| Garlic | — | — | — | Oct 4 – Nov 8 |
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 Burlington, CT weather station, 26 km away (elevation 505 ft (154 m)).
Frost dates near Watertown
- Oakville Apr 26 · Oct 16
- Middlebury Apr 25 · Oct 17
- Bethlehem May 8 · Oct 5
- Waterbury Apr 26 · Oct 16
- Thomaston Apr 25 · Oct 18
- Plymouth Apr 25 · Oct 18
- Woodbury Apr 20 · Oct 20
- Morris May 8 · Oct 5
- Northfield May 8 · Oct 5
- Wolcott Apr 26 · Oct 16
Frequently asked questions
When is the last frost in Watertown, CT?
The median last spring frost in Watertown, CT is April 25. There is still about a 10% chance of frost after May 10, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Watertown, CT?
The median first fall frost is October 18, with about a 10% chance of frost before October 4.
How long is the growing season in Watertown, CT?
About 176 days between the median last spring frost and first fall frost.
What planting zone is Watertown, CT?
Watertown, CT is in USDA hardiness zone 6b.