Holmen Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for La Crosse 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 23 and the first fall freeze around October 17, a growing season of about 177 days.
- Median at 36°F
- last May 4, first October 6
- Median at 32°F
- last April 23, first October 17
- Median at 28°F
- last April 12, first October 28
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 17 | May 12 | May 9 | May 6 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 21 |
| 32°F | May 6 | May 2 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 14 | Apr 9 |
| 28°F | Apr 27 | Apr 21 | Apr 18 | Apr 14 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Mar 31 |
| 24°F | Apr 16 | Apr 10 | Apr 7 | Apr 4 | Apr 2 | Mar 31 | Mar 29 | Mar 24 | Mar 19 |
| 20°F | Apr 6 | Apr 2 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 10 |
| 16°F | Mar 31 | Mar 27 | Mar 23 | Mar 21 | Mar 18 | Mar 15 | Mar 12 | Mar 9 | Mar 4 |
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 1 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 16 | Oct 21 |
| 32°F | Oct 3 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 28°F | Oct 15 | Oct 19 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 11 |
| 24°F | Oct 27 | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 21 |
| 20°F | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 21 | Nov 25 | Nov 29 |
| 16°F | Nov 10 | Nov 14 | Nov 18 | Nov 21 | Nov 24 | Nov 26 | Nov 29 | Dec 3 | Dec 8 |
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 | 174 | 167 | 163 | 159 | 155 | 152 | 149 | 144 | 138 |
| 32°F | 196 | 191 | 185 | 181 | 177 | 173 | 169 | 165 | 158 |
| 28°F | 217 | 210 | 206 | 202 | 198 | 194 | 191 | 186 | 179 |
| 24°F | 236 | 230 | 225 | 221 | 218 | 214 | 210 | 206 | 200 |
| 20°F | 255 | 248 | 243 | 239 | 235 | 231 | 227 | 222 | 216 |
| 16°F | 271 | 263 | 259 | 256 | 251 | 246 | 242 | 237 | 231 |
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
- 6,788
- Cooling degree days, base 65°F
- 942
- Growing degree days, base 40°F
- 5,293
- Growing degree days, base 45°F
- 4,190
- Growing degree days, base 50°F
- 3,200
- Growing degree days, base 55°F
- 2,327
- Growing degree days, base 60°F
- 1,570
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,427 | 0 | 0 |
| February | 1,166 | 0 | 1 |
| March | 907 | 1 | 21 |
| April | 486 | 6 | 103 |
| May | 181 | 59 | 353 |
| June | 24 | 206 | 631 |
| July | 3 | 311 | 773 |
| August | 8 | 248 | 705 |
| September | 105 | 99 | 448 |
| October | 422 | 12 | 146 |
| November | 821 | 0 | 18 |
| December | 1,237 | 0 | 1 |
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 9.4 km from Holmen. 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 USW00014920 (La Crosse Muni AP). Public domain.