Harman US

Frost Dates for Williamson, NY

Last spring frost
May 6
First fall frost
Oct 10
Growing season
158 days
Hardiness zone
6b

In an average year around Williamson, NY, the last spring frost (32°F) is about May 6 and the first fall frost is about Oct 10, giving roughly a 158-day growing season. To be safe most years, wait until Apr 24 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.

Last spring frost - Williamson, NY
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Jun 3 May 19 May 4
Freeze (32°F) May 21 May 6 Apr 24
Hard (28°F) May 12 Apr 25 Apr 10
Severe (24°F) Apr 30 Apr 12 Mar 31
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Jun 3 May 29 May 25 May 22 May 19 May 16 May 13 May 9 May 4
32°F May 21 May 16 May 13 May 9 May 6 May 3 Apr 30 Apr 28 Apr 24
28°F May 12 May 5 May 1 Apr 28 Apr 25 Apr 23 Apr 19 Apr 16 Apr 10
24°F Apr 30 Apr 23 Apr 19 Apr 16 Apr 12 Apr 9 Apr 6 Apr 3 Mar 31
20°F Apr 15 Apr 8 Apr 5 Apr 3 Apr 1 Mar 31 Mar 27 Mar 23 Mar 17
16°F Apr 4 Apr 1 Mar 29 Mar 26 Mar 23 Mar 20 Mar 17 Mar 13 Mar 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.

First fall frost - Williamson, NY
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Sep 16 Sep 29 Oct 13
Freeze (32°F) Sep 27 Oct 10 Oct 28
Hard (28°F) Oct 6 Oct 25 Nov 8
Severe (24°F) Oct 21 Nov 6 Nov 23
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Sep 16 Sep 21 Sep 24 Sep 27 Sep 29 Oct 1 Oct 4 Oct 7 Oct 13
32°F Sep 27 Oct 1 Oct 4 Oct 7 Oct 10 Oct 14 Oct 17 Oct 22 Oct 28
28°F Oct 6 Oct 12 Oct 17 Oct 21 Oct 25 Oct 29 Nov 1 Nov 3 Nov 8
24°F Oct 21 Oct 28 Nov 1 Nov 3 Nov 6 Nov 9 Nov 13 Nov 17 Nov 23
20°F Nov 3 Nov 8 Nov 12 Nov 15 Nov 19 Nov 22 Nov 26 Dec 1 Dec 5
16°F Nov 14 Nov 19 Nov 23 Nov 27 Dec 1 Dec 3 Dec 7 Dec 11 Dec 18

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

These dates are computed from the nearest official weather station with long-term records: Sodus 1W, Ny, about 4.3 miles away@if(!empty($station['elevation_ft'])), at 444 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

@endif
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 Williamson, NY?

On average, the last spring frost (32°F) around Williamson, NY is about May 6. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 24.

When is the first frost in the fall?

The first fall frost around Williamson, NY typically arrives about Oct 10. 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 May 6 on average, or Apr 24 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 158 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 14589 Planting calendar → New York frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026