Goodwell Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Goodwell Rsch Stn. 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 19, a growing season of about 178 days.
- Median at 36°F
- last May 2, first October 11
- Median at 32°F
- last April 24, first October 19
- Median at 28°F
- last April 13, first October 29
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 14 | May 10 | May 8 | May 5 | May 2 | Apr 30 | Apr 28 | Apr 24 | Apr 19 |
| 32°F | May 6 | May 2 | Apr 29 | Apr 27 | Apr 24 | Apr 20 | Apr 17 | Apr 13 | Apr 8 |
| 28°F | Apr 27 | Apr 23 | Apr 19 | Apr 16 | Apr 13 | Apr 9 | Apr 5 | Apr 1 | Mar 27 |
| 24°F | Apr 18 | Apr 13 | Apr 8 | Apr 4 | Apr 1 | Mar 29 | Mar 25 | Mar 20 | Mar 13 |
| 20°F | Apr 7 | Apr 2 | Mar 30 | Mar 24 | Mar 20 | Mar 16 | Mar 12 | Mar 8 | Mar 1 |
| 16°F | Mar 30 | Mar 21 | Mar 17 | Mar 12 | Mar 8 | Mar 3 | Feb 28 | Feb 23 | Feb 15 |
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 5 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 18 | Oct 22 |
| 32°F | Oct 6 | Oct 11 | Oct 15 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 28°F | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 11 |
| 24°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 16 | Nov 21 |
| 20°F | Oct 31 | Nov 5 | Nov 9 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 26 | Dec 1 |
| 16°F | Nov 6 | Nov 12 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 1 | Dec 6 | Dec 13 |
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 | 179 | 173 | 168 | 163 | 159 | 156 | 152 | 148 | 142 |
| 32°F | 195 | 190 | 185 | 182 | 178 | 174 | 170 | 165 | 159 |
| 28°F | 217 | 210 | 205 | 201 | 196 | 192 | 188 | 183 | 177 |
| 24°F | 240 | 232 | 225 | 220 | 216 | 212 | 207 | 202 | 194 |
| 20°F | 264 | 256 | 249 | 243 | 237 | 233 | 227 | 222 | 213 |
| 16°F | 287 | 277 | 270 | 265 | 260 | 255 | 249 | 243 | 233 |
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
- 4,673
- Cooling degree days, base 65°F
- 1,380
- Growing degree days, base 40°F
- 6,577
- Growing degree days, base 45°F
- 5,234
- Growing degree days, base 50°F
- 4,051
- Growing degree days, base 55°F
- 3,020
- Growing degree days, base 60°F
- 2,130
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 950 | 0 | 4 |
| February | 776 | 0 | 12 |
| March | 598 | 1 | 70 |
| April | 342 | 12 | 184 |
| May | 119 | 88 | 441 |
| June | 9 | 290 | 732 |
| July | 1 | 424 | 888 |
| August | 3 | 370 | 832 |
| September | 47 | 172 | 576 |
| October | 281 | 23 | 251 |
| November | 613 | 1 | 55 |
| December | 934 | 0 | 5 |
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 1.6 km from Goodwell. 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 USC00343628 (Goodwell Rsch Stn). Public domain.