Hooven Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Cincinnati-Fernbank. A median date has an even chance of a later freeze in spring, or an earlier one in fall.
The last spring freeze typically comes around April 13 and the first fall freeze around October 31, a growing season of about 197 days.
- Median at 36°F
- last April 26, first October 20
- Median at 32°F
- last April 13, first October 31
- Median at 28°F
- last March 31, first November 10
Last freeze in spring
The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 13 | May 7 | May 3 | Apr 29 | Apr 26 | Apr 23 | Apr 20 | Apr 16 | Apr 12 |
| 32°F | May 2 | Apr 24 | Apr 20 | Apr 16 | Apr 13 | Apr 10 | Apr 7 | Apr 3 | Mar 31 |
| 28°F | Apr 15 | Apr 9 | Apr 5 | Apr 3 | Mar 31 | Mar 29 | Mar 26 | Mar 22 | Mar 16 |
| 24°F | Apr 3 | Mar 30 | Mar 26 | Mar 23 | Mar 20 | Mar 17 | Mar 13 | Mar 8 | Mar 2 |
| 20°F | Mar 25 | Mar 20 | Mar 16 | Mar 12 | Mar 8 | Mar 4 | Mar 1 | Feb 24 | Feb 15 |
| 16°F | Mar 17 | Mar 11 | Mar 6 | Mar 2 | Feb 28 | Feb 23 | Feb 17 | Feb 10 | Feb 2 |
First freeze in fall
The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 24 | Oct 27 | Nov 1 |
| 32°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 13 |
| 28°F | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 22 | Nov 29 |
| 24°F | Nov 6 | Nov 11 | Nov 15 | Nov 19 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 12 |
| 20°F | Nov 17 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 16 | Dec 21 | Dec 26 |
| 16°F | Nov 29 | Dec 4 | Dec 10 | Dec 15 | Dec 20 | Dec 23 | Dec 28 | Jan 1 | Jan 10 |
Growing season length
Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | 194 | 188 | 182 | 178 | 174 | 170 | 165 | 161 | 155 |
| 32°F | 219 | 211 | 206 | 201 | 197 | 192 | 187 | 182 | 175 |
| 28°F | 248 | 239 | 234 | 229 | 225 | 220 | 216 | 210 | 202 |
| 24°F | 275 | 266 | 261 | 255 | 251 | 245 | 240 | 234 | 227 |
| 20°F | 300 | 290 | 283 | 278 | 272 | 266 | 261 | 254 | 246 |
| 16°F | 323 | 314 | 306 | 301 | 296 | 291 | 284 | 277 | 268 |
How often it gets that cold
The share of years with at least one night at or below each temperature.
- 36°F or colder
- 100% of years
- 32°F or colder
- 100% of years
- 28°F or colder
- 100% of years
- 24°F or colder
- 100% of years
- 20°F or colder
- 100% of years
- 16°F or colder
- 100% of years
Degree days
A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.
- Heating degree days, base 65°F
- 4,773
- Cooling degree days, base 65°F
- 1,176
- Growing degree days, base 40°F
- 6,347
- Growing degree days, base 45°F
- 5,026
- Growing degree days, base 50°F
- 3,853
- Growing degree days, base 55°F
- 2,820
- Growing degree days, base 60°F
- 1,926
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,021 | 0 | 9 |
| February | 841 | 0 | 10 |
| March | 664 | 3 | 62 |
| April | 337 | 17 | 194 |
| May | 114 | 89 | 444 |
| June | 13 | 238 | 675 |
| July | 0 | 344 | 809 |
| August | 2 | 313 | 776 |
| September | 47 | 149 | 552 |
| October | 278 | 22 | 241 |
| November | 580 | 1 | 65 |
| December | 877 | 0 | 14 |
What this means
NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.
The station is 8.7 km from Hooven. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.
More
Sources
NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00331550 (Cincinnati-Fernbank). Public domain.