Odon Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Elnora. 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 9 and the first fall freeze around October 25, a growing season of about 197 days.
- Median at 36°F
- last April 21, first October 15
- Median at 32°F
- last April 9, first October 25
- Median at 28°F
- last March 31, first November 4
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 6 | Apr 30 | Apr 27 | Apr 24 | Apr 21 | Apr 18 | Apr 14 | Apr 10 | Apr 6 |
| 32°F | Apr 25 | Apr 20 | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Apr 1 | Mar 27 |
| 28°F | Apr 15 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 19 | Mar 13 |
| 24°F | Apr 3 | Mar 29 | Mar 25 | Mar 22 | Mar 18 | Mar 15 | Mar 11 | Mar 7 | Mar 1 |
| 20°F | Mar 23 | Mar 18 | Mar 15 | Mar 11 | Mar 8 | Mar 4 | Mar 1 | Feb 25 | Feb 16 |
| 16°F | Mar 16 | Mar 12 | Mar 7 | Mar 3 | Feb 28 | Feb 25 | Feb 19 | Feb 12 | 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 1 | Oct 6 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 28 |
| 32°F | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 7 |
| 28°F | Oct 22 | Oct 27 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 12 | Nov 16 | Nov 22 |
| 24°F | Nov 1 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 24 | Nov 28 | Dec 4 |
| 20°F | Nov 10 | Nov 16 | Nov 21 | Nov 26 | Nov 29 | Dec 2 | Dec 6 | Dec 10 | Dec 18 |
| 16°F | Nov 19 | Nov 27 | Dec 1 | Dec 5 | Dec 9 | Dec 13 | Dec 19 | Dec 24 | Dec 30 |
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 | 196 | 189 | 183 | 179 | 175 | 171 | 168 | 162 | 156 |
| 32°F | 218 | 210 | 206 | 201 | 197 | 193 | 189 | 183 | 177 |
| 28°F | 241 | 233 | 228 | 224 | 219 | 214 | 209 | 205 | 197 |
| 24°F | 267 | 258 | 251 | 247 | 242 | 238 | 233 | 227 | 219 |
| 20°F | 292 | 283 | 275 | 270 | 265 | 259 | 254 | 248 | 241 |
| 16°F | 315 | 303 | 297 | 291 | 285 | 280 | 274 | 267 | 257 |
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
- 4,622
- Cooling degree days, base 65°F
- 1,314
- Growing degree days, base 40°F
- 6,641
- Growing degree days, base 45°F
- 5,302
- Growing degree days, base 50°F
- 4,106
- Growing degree days, base 55°F
- 3,043
- Growing degree days, base 60°F
- 2,113
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,044 | 0 | 4 |
| February | 823 | 0 | 15 |
| March | 599 | 4 | 81 |
| April | 271 | 21 | 242 |
| May | 80 | 131 | 517 |
| June | 3 | 274 | 721 |
| July | 1 | 362 | 826 |
| August | 2 | 316 | 780 |
| September | 41 | 166 | 575 |
| October | 254 | 36 | 278 |
| November | 598 | 2 | 57 |
| December | 907 | 0 | 10 |
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 9.2 km from Odon. 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 USC00122620 (Elnora). Public domain.