Dublin Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Columbus Ohio State Univ AP. 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 22 and the first fall freeze around October 23, a growing season of about 183 days.
- Median at 36°F
- last May 3, first October 12
- Median at 32°F
- last April 22, first October 23
- Median at 28°F
- last April 9, first November 2
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 20 | May 14 | May 9 | May 6 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 18 |
| 32°F | May 9 | May 3 | Apr 30 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 6 |
| 28°F | Apr 26 | Apr 19 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 24 |
| 24°F | Apr 13 | Apr 7 | Apr 4 | Apr 1 | Mar 30 | Mar 27 | Mar 23 | Mar 19 | Mar 13 |
| 20°F | Apr 2 | Mar 30 | Mar 27 | Mar 23 | Mar 20 | Mar 17 | Mar 13 | Mar 8 | Mar 1 |
| 16°F | Mar 27 | Mar 22 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 2 | Feb 25 | Feb 19 |
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 | Sep 28 | Oct 2 | Oct 6 | Oct 10 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 24 |
| 32°F | Oct 9 | Oct 15 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Nov 1 | Nov 4 |
| 28°F | Oct 20 | Oct 25 | Oct 29 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 11 | Nov 15 |
| 24°F | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 13 | Nov 16 | Nov 19 | Nov 24 | Dec 1 |
| 20°F | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 26 | Nov 30 | Dec 3 | Dec 8 | Dec 15 |
| 16°F | Nov 18 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 17 | Dec 22 | Dec 29 |
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 | 181 | 175 | 170 | 165 | 162 | 158 | 154 | 149 | 141 |
| 32°F | 202 | 195 | 190 | 186 | 183 | 179 | 174 | 169 | 163 |
| 28°F | 226 | 218 | 214 | 210 | 206 | 201 | 197 | 192 | 185 |
| 24°F | 252 | 244 | 239 | 234 | 230 | 226 | 221 | 216 | 209 |
| 20°F | 278 | 268 | 261 | 257 | 252 | 247 | 242 | 236 | 230 |
| 16°F | 301 | 292 | 286 | 280 | 276 | 269 | 263 | 256 | 248 |
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
- 5,486
- Cooling degree days, base 65°F
- 919
- Growing degree days, base 40°F
- 5,697
- Growing degree days, base 45°F
- 4,463
- Growing degree days, base 50°F
- 3,370
- Growing degree days, base 55°F
- 2,412
- Growing degree days, base 60°F
- 1,592
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,122 | 0 | 4 |
| February | 938 | 0 | 7 |
| March | 759 | 2 | 43 |
| April | 397 | 10 | 151 |
| May | 155 | 69 | 387 |
| June | 21 | 193 | 622 |
| July | 2 | 285 | 749 |
| August | 5 | 245 | 705 |
| September | 78 | 100 | 474 |
| October | 354 | 15 | 182 |
| November | 675 | 0 | 37 |
| December | 981 | 0 | 8 |
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 3.8 km from Dublin. 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 USW00004804 (Columbus Ohio State Univ AP). Public domain.