Last spring frost
Apr 25
Frost Dates for Canton Valley, CT
First fall frost
Oct 18
Growing season
172 days
Hardiness zone
6a
In an average year around Canton Valley, CT, the last spring frost (32°F) is about Apr 25 and the first fall frost is about Oct 18, giving roughly a 172-day growing season. To be safe most years, wait until Apr 12 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 22 | May 6 | Apr 24 |
| Freeze (32°F) | May 10 | Apr 25 | Apr 12 |
| Hard (28°F) | Apr 29 | Apr 13 | Apr 2 |
| Severe (24°F) | Apr 14 | Apr 2 | Mar 19 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 22 | May 17 | May 13 | May 9 | May 6 | May 4 | May 1 | Apr 28 | Apr 24 |
| 32°F | May 10 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 23 | Apr 20 | Apr 17 | Apr 12 |
| 28°F | Apr 29 | Apr 22 | Apr 18 | Apr 16 | Apr 13 | Apr 10 | Apr 7 | Apr 5 | Apr 2 |
| 24°F | Apr 14 | Apr 8 | Apr 5 | Apr 4 | Apr 2 | Mar 31 | Mar 29 | Mar 24 | Mar 19 |
| 20°F | Apr 3 | Mar 31 | Mar 28 | Mar 24 | Mar 22 | Mar 19 | Mar 16 | Mar 13 | Mar 8 |
| 16°F | Mar 28 | Mar 23 | Mar 19 | Mar 16 | Mar 14 | Mar 11 | Mar 8 | Mar 4 | Feb 28 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 26 | Oct 6 | Oct 20 |
| Freeze (32°F) | Oct 4 | Oct 18 | Nov 1 |
| Hard (28°F) | Oct 14 | Oct 30 | Nov 14 |
| Severe (24°F) | Oct 26 | Nov 11 | Dec 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 26 | Sep 30 | Oct 2 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 16 | Oct 20 |
| 32°F | Oct 4 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 24 | Oct 27 | Nov 1 |
| 28°F | Oct 14 | Oct 19 | Oct 22 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 9 | Nov 14 |
| 24°F | Oct 26 | Nov 1 | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 24 | Dec 1 |
| 20°F | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 28 | Dec 1 | Dec 3 | Dec 6 | Dec 11 |
| 16°F | Nov 21 | Nov 27 | Dec 1 | Dec 3 | Dec 6 | Dec 9 | Dec 13 | Dec 18 | Dec 24 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Burlington, Ct, about 4.6 miles away@if(!empty($station['elevation_ft'])), at 505 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Canton Valley, CT?
On average, the last spring frost (32°F) around Canton Valley, CT is about Apr 25. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 12.
When is the first frost in the fall?
The first fall frost around Canton Valley, CT typically arrives about Oct 18. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 25 on average, or Apr 12 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 172 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 06019 Planting calendar → Connecticut frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026