Last spring frost
Apr 12
Frost Dates for Rye Brook, CT
First fall frost
Oct 31
Growing season
200 days
Hardiness zone
7a
In an average year around Rye Brook, CT, the last spring frost (32°F) is about Apr 12 and the first fall frost is about Oct 31, giving roughly a 200-day growing season. To be safe most years, wait until Apr 1 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 11 | Apr 26 | Apr 13 |
| Freeze (32°F) | Apr 27 | Apr 12 | Apr 1 |
| Hard (28°F) | Apr 13 | Apr 1 | Mar 18 |
| Severe (24°F) | Apr 3 | Mar 21 | Mar 6 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 11 | May 6 | May 2 | Apr 30 | Apr 26 | Apr 23 | Apr 20 | Apr 17 | Apr 13 |
| 32°F | Apr 27 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 10 | Apr 7 | Apr 5 | Apr 1 |
| 28°F | Apr 13 | Apr 8 | Apr 5 | Apr 3 | Apr 1 | Mar 31 | Mar 28 | Mar 24 | Mar 18 |
| 24°F | Apr 3 | Mar 31 | Mar 28 | Mar 25 | Mar 21 | Mar 18 | Mar 15 | Mar 11 | Mar 6 |
| 20°F | Mar 27 | Mar 21 | Mar 17 | Mar 14 | Mar 11 | Mar 8 | Mar 5 | Mar 1 | Feb 25 |
| 16°F | Mar 17 | Mar 12 | Mar 8 | Mar 5 | Mar 2 | Feb 27 | Feb 24 | Feb 18 | Feb 9 |
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) | Oct 2 | Oct 18 | Nov 2 |
| Freeze (32°F) | Oct 15 | Oct 31 | Nov 14 |
| Hard (28°F) | Oct 29 | Nov 13 | Nov 29 |
| Severe (24°F) | Nov 10 | Nov 25 | Dec 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 2 | Oct 8 | Oct 11 | Oct 15 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 2 |
| 32°F | Oct 15 | Oct 21 | Oct 24 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 9 | Nov 14 |
| 28°F | Oct 29 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 18 | Nov 22 | Nov 29 |
| 24°F | Nov 10 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 10 |
| 20°F | Nov 21 | Nov 27 | Nov 30 | Dec 3 | Dec 6 | Dec 10 | Dec 15 | Dec 20 | Dec 25 |
| 16°F | Dec 2 | Dec 7 | Dec 13 | Dec 17 | Dec 21 | Dec 25 | Dec 29 | Jan 3 | Jan 10 |
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: Westchester Co Ap, Ny, about 3 miles away@if(!empty($station['elevation_ft'])), at 379 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 Rye Brook, CT?
On average, the last spring frost (32°F) around Rye Brook, CT is about Apr 12. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 1.
When is the first frost in the fall?
The first fall frost around Rye Brook, CT typically arrives about Oct 31. 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 12 on average, or Apr 1 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 200 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 06831 Planting calendar → Connecticut frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026