Last spring frost
Apr 24
Frost Dates for Casstown, OH
First fall frost
Oct 17
Growing season
173 days
Hardiness zone
6a
In an average year around Casstown, OH, the last spring frost (32°F) is about Apr 24 and the first fall frost is about Oct 17, giving roughly a 173-day growing season. To be safe most years, wait until Apr 10 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 21 | May 4 | Apr 20 |
| Freeze (32°F) | May 10 | Apr 24 | Apr 10 |
| Hard (28°F) | Apr 28 | Apr 12 | Mar 31 |
| Severe (24°F) | Apr 14 | Apr 1 | Mar 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 21 | May 15 | May 10 | May 7 | May 4 | May 1 | Apr 29 | Apr 24 | Apr 20 |
| 32°F | May 10 | May 5 | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 19 | Apr 15 | Apr 10 |
| 28°F | Apr 28 | Apr 22 | Apr 18 | Apr 15 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Mar 31 |
| 24°F | Apr 14 | Apr 9 | Apr 6 | Apr 3 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 17 |
| 20°F | Apr 4 | Mar 31 | Mar 29 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 11 | Mar 4 |
| 16°F | Mar 28 | Mar 22 | Mar 18 | Mar 14 | Mar 12 | Mar 8 | Mar 5 | Feb 28 | Feb 21 |
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 23 | Oct 5 | Oct 17 |
| Freeze (32°F) | Oct 4 | Oct 17 | Oct 29 |
| Hard (28°F) | Oct 13 | Oct 27 | Nov 9 |
| Severe (24°F) | Oct 25 | Nov 7 | Nov 25 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 23 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 10 | Oct 14 | Oct 17 |
| 32°F | Oct 4 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 29 |
| 28°F | Oct 13 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 24°F | Oct 25 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 10 | Nov 15 | Nov 19 | Nov 25 |
| 20°F | Nov 5 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 24 | Nov 29 | Dec 3 | Dec 12 |
| 16°F | Nov 14 | Nov 21 | Nov 26 | Dec 1 | Dec 3 | Dec 7 | Dec 14 | Dec 20 | Dec 25 |
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: New Carlisle, Oh, about 8.9 miles away@if(!empty($station['elevation_ft'])), at 874 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 Casstown, OH?
On average, the last spring frost (32°F) around Casstown, OH is about Apr 24. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 10.
When is the first frost in the fall?
The first fall frost around Casstown, OH typically arrives about Oct 17. 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 10 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 173 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 45312 Planting calendar → Ohio frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026