Frost dates / Ohio / Hamilton
Frost dates in Hamilton, OH
The station on this page is HAMILTON BUTLER CO RGNL AP, OH US (USW00053855), 3 miles from the city point. Population in the Census 2024 estimate is 63,953.
Zone 6bUSDA average annual extreme minimum -5°F to 0°F, from ZIP 45015 (1.4 miles from the city point used on this page).
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Last 32°F in spring
NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.
| Probability | Date | How to read it |
|---|---|---|
| 90% | April 6 | Earlier date. A last 32°F on or after this day is common. |
| 50% | April 22 | Median. |
| 10% | May 10 | Later date. A last 32°F on or after this day is uncommon. |
First 32°F in fall
NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.
| Probability | Date | How to read it |
|---|---|---|
| 10% | October 5 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | October 18 | Median. |
| 90% | October 29 | Later date. A first 32°F on or before this day is common. |
32°F growing-season length
Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.
| Probability the season is at least this long | Days |
|---|---|
| 10% | 198 |
| 50% | 178 |
| 90% | 157 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 28 | April 8 | March 26 |
| First, on or before | October 15 | October 27 | November 8 |
| Season at least | 221 days | 200 days | 178 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | May 19 | May 2 | April 18 |
| First, on or before | September 25 | October 7 | October 20 |
| Season at least | 177 days | 159 days | 138 days |
Station HAMILTON BUTLER CO RGNL AP, OH US (USW00053855). Completeness flag R, 21 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 193.2 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.
Planting calendar for Hamilton · Zone 6b
Check a crop against this station
Hamilton, OH
Zone 6bAverage annual extreme minimum -5°F to 0°F
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Ohio. Nearest qualified station: HAMILTON BUTLER CO RGNL AP, OH US (USW00053855), 3 miles. Median last 32°F April 22. Median first 32°F October 18. The 50% growing-season length is 178 days.
Open the ZIP page · Crop guides for Ohio
32°F probabilities at this station
| 10% | 50% | 90% | |
|---|---|---|---|
| Last 32°F on or after | May 10 | April 22 | April 6 |
| First 32°F on or before | October 5 | October 18 | October 29 |
Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.
Planting calendar
Windows below are from Ohio State University Extension, Planning for the Garden, excerpted from OSU Extension Bulletin 287, Home Vegetable Gardening, retrieved 2026-10-10. The dates are for a normal season in central Ohio. The same page says spring planting runs about two weeks earlier in southern Ohio and about two weeks later in northern Ohio. Those shifts are a sentence, not a second column, so the dates below stay the central Ohio dates. The PDF says the tables are excerpted from Bulletin 287 by Utzinger, Brooks and Wittmeyer, 1991, now out of print.
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