Cardington Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Marion Muni 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 24 and the first fall freeze around October 20, a growing season of about 178 days.
- Median at 36°F
- last May 4, first October 7
- Median at 32°F
- last April 24, first October 20
- Median at 28°F
- last April 15, first October 31
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 19 | May 14 | May 10 | May 7 | May 4 | May 1 | Apr 29 | Apr 25 | Apr 22 |
| 32°F | May 10 | May 4 | May 1 | Apr 28 | Apr 24 | Apr 22 | Apr 19 | Apr 16 | Apr 11 |
| 28°F | Apr 30 | Apr 24 | Apr 20 | Apr 17 | Apr 15 | Apr 11 | Apr 7 | Apr 4 | Mar 31 |
| 24°F | Apr 17 | Apr 13 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 18 |
| 20°F | Apr 6 | Apr 2 | Mar 30 | Mar 27 | Mar 23 | Mar 21 | Mar 17 | Mar 12 | Mar 6 |
| 16°F | Mar 30 | Mar 24 | Mar 21 | Mar 17 | Mar 13 | Mar 10 | Mar 6 | Mar 2 | Feb 24 |
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 24 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 |
| 32°F | Oct 5 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Nov 1 |
| 28°F | Oct 18 | Oct 23 | Oct 26 | Oct 29 | Oct 31 | Nov 2 | Nov 5 | Nov 9 | Nov 13 |
| 24°F | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 21 | Nov 27 |
| 20°F | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 4 | Dec 12 |
| 16°F | Nov 15 | Nov 21 | Nov 26 | Dec 1 | Dec 4 | Dec 7 | Dec 12 | Dec 17 | Dec 23 |
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 | 175 | 168 | 164 | 160 | 157 | 152 | 148 | 143 | 136 |
| 32°F | 197 | 191 | 186 | 182 | 178 | 174 | 170 | 165 | 159 |
| 28°F | 221 | 214 | 209 | 205 | 201 | 197 | 193 | 188 | 181 |
| 24°F | 245 | 237 | 232 | 227 | 222 | 219 | 215 | 210 | 204 |
| 20°F | 268 | 260 | 255 | 250 | 245 | 239 | 235 | 229 | 221 |
| 16°F | 292 | 284 | 277 | 271 | 266 | 261 | 255 | 249 | 240 |
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
- 5,901
- Cooling degree days, base 65°F
- 779
- Growing degree days, base 40°F
- 5,349
- Growing degree days, base 45°F
- 4,161
- Growing degree days, base 50°F
- 3,109
- Growing degree days, base 55°F
- 2,194
- Growing degree days, base 60°F
- 1,414
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,189 | 0 | 2 |
| February | 1,000 | 0 | 5 |
| March | 822 | 1 | 30 |
| April | 454 | 6 | 118 |
| May | 177 | 56 | 355 |
| June | 28 | 173 | 595 |
| July | 4 | 252 | 713 |
| August | 8 | 199 | 656 |
| September | 97 | 80 | 436 |
| October | 382 | 13 | 164 |
| November | 711 | 0 | 30 |
| December | 1,031 | 0 | 6 |
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 19.3 km from Cardington. 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 USW00004855 (Marion Muni AP). Public domain.