Harman US

Frost Dates for Hamler, OH

Last spring frost
Apr 24
First fall frost
Oct 21
Growing season
179 days
Hardiness zone
6a

In an average year around Hamler, OH, the last spring frost (32°F) is about Apr 24 and the first fall frost is about Oct 21, giving roughly a 179-day growing season. To be safe most years, wait until Apr 13 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 - Hamler, OH
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) May 17 May 2 Apr 21
Freeze (32°F) May 7 Apr 24 Apr 13
Hard (28°F) Apr 26 Apr 14 Mar 31
Severe (24°F) Apr 17 Apr 4 Mar 20
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F May 17 May 11 May 7 May 4 May 2 Apr 30 Apr 28 Apr 25 Apr 21
32°F May 7 May 2 Apr 29 Apr 26 Apr 24 Apr 21 Apr 19 Apr 17 Apr 13
28°F Apr 26 Apr 22 Apr 19 Apr 17 Apr 14 Apr 11 Apr 9 Apr 5 Mar 31
24°F Apr 17 Apr 13 Apr 9 Apr 6 Apr 4 Apr 1 Mar 30 Mar 26 Mar 20
20°F Apr 8 Apr 3 Mar 31 Mar 29 Mar 25 Mar 22 Mar 18 Mar 14 Mar 9
16°F Mar 31 Mar 26 Mar 21 Mar 17 Mar 15 Mar 12 Mar 8 Mar 5 Feb 27

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 - Hamler, OH
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Sep 27 Oct 9 Oct 23
Freeze (32°F) Oct 5 Oct 21 Nov 3
Hard (28°F) Oct 18 Nov 1 Nov 15
Severe (24°F) Oct 31 Nov 11 Nov 29
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Sep 27 Oct 1 Oct 4 Oct 7 Oct 9 Oct 12 Oct 15 Oct 18 Oct 23
32°F Oct 5 Oct 11 Oct 15 Oct 18 Oct 21 Oct 24 Oct 27 Oct 31 Nov 3
28°F Oct 18 Oct 24 Oct 28 Oct 31 Nov 1 Nov 4 Nov 6 Nov 10 Nov 15
24°F Oct 31 Nov 3 Nov 5 Nov 8 Nov 11 Nov 15 Nov 18 Nov 22 Nov 29
20°F Nov 6 Nov 12 Nov 16 Nov 19 Nov 24 Nov 28 Dec 1 Dec 5 Dec 12
16°F Nov 16 Nov 22 Nov 27 Dec 1 Dec 4 Dec 7 Dec 12 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

These dates are computed from the nearest official weather station with long-term records: Napoleon, Oh, about 12.2 miles away@if(!empty($station['elevation_ft'])), at 682 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

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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 Hamler, OH?

On average, the last spring frost (32°F) around Hamler, OH is about Apr 24. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 13.

When is the first frost in the fall?

The first fall frost around Hamler, OH typically arrives about Oct 21. 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 24 on average, or Apr 13 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 179 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 43524 Planting calendar → Ohio frost dates →

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