Aberdeen Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Maysville Wwtp. 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 18 and the first fall freeze around October 30, a growing season of about 195 days.
- Median at 36°F
- last April 29, first October 19
- Median at 32°F
- last April 18, first October 30
- Median at 28°F
- last April 5, first November 8
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 15 | May 9 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 19 | Apr 15 |
| 32°F | May 4 | Apr 29 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 8 | Apr 3 |
| 28°F | Apr 22 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 21 |
| 24°F | Apr 9 | Apr 3 | Apr 1 | Mar 30 | Mar 26 | Mar 21 | Mar 17 | Mar 13 | Mar 6 |
| 20°F | Apr 1 | Mar 26 | Mar 21 | Mar 17 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 23 |
| 16°F | Mar 22 | Mar 15 | Mar 9 | Mar 5 | Mar 1 | Feb 26 | Feb 22 | Feb 15 | Feb 6 |
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 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 |
| 32°F | Oct 17 | Oct 21 | Oct 24 | Oct 28 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 |
| 28°F | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 10 | Nov 13 | Nov 16 | Nov 21 |
| 24°F | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 28 | Dec 3 |
| 20°F | Nov 10 | Nov 16 | Nov 20 | Nov 25 | Nov 29 | Dec 2 | Dec 5 | Dec 11 | Dec 20 |
| 16°F | Nov 20 | Nov 29 | Dec 4 | Dec 8 | Dec 13 | Dec 19 | Dec 25 | Dec 30 | Jan 5 |
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 | 191 | 185 | 181 | 176 | 173 | 169 | 165 | 160 | 152 |
| 32°F | 212 | 206 | 202 | 198 | 195 | 192 | 188 | 182 | 175 |
| 28°F | 235 | 229 | 224 | 219 | 215 | 212 | 208 | 203 | 197 |
| 24°F | 261 | 253 | 247 | 241 | 236 | 232 | 227 | 222 | 216 |
| 20°F | 290 | 281 | 273 | 267 | 261 | 256 | 249 | 243 | 234 |
| 16°F | 318 | 306 | 300 | 293 | 287 | 281 | 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
- 4,850
- Cooling degree days, base 65°F
- 1,133
- Growing degree days, base 40°F
- 6,233
- Growing degree days, base 45°F
- 4,923
- Growing degree days, base 50°F
- 3,760
- Growing degree days, base 55°F
- 2,740
- Growing degree days, base 60°F
- 1,867
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,023 | 0 | 7 |
| February | 847 | 0 | 8 |
| March | 685 | 1 | 45 |
| April | 348 | 10 | 178 |
| May | 126 | 77 | 419 |
| June | 14 | 224 | 660 |
| July | 1 | 340 | 804 |
| August | 2 | 305 | 769 |
| September | 42 | 153 | 561 |
| October | 275 | 23 | 244 |
| November | 605 | 1 | 53 |
| December | 884 | 0 | 13 |
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 4.1 km from Aberdeen. 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 USC00155243 (Maysville Wwtp). Public domain.