Dodge County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Horicon 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 May 1 and the first fall freeze around October 10, a growing season of about 158 days.
- Median at 36°F
- last May 13, first October 1
- Median at 32°F
- last May 1, first October 10
- Median at 28°F
- last April 20, first October 21
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 30 | May 24 | May 21 | May 17 | May 13 | May 10 | May 7 | May 3 | Apr 29 |
| 32°F | May 19 | May 13 | May 8 | May 5 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 16 |
| 28°F | May 5 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 14 | Apr 10 | Apr 6 |
| 24°F | Apr 25 | Apr 19 | Apr 15 | Apr 11 | Apr 8 | Apr 6 | Apr 3 | Apr 1 | Mar 26 |
| 20°F | Apr 12 | Apr 7 | Apr 4 | Apr 2 | Mar 31 | Mar 27 | Mar 24 | Mar 20 | Mar 15 |
| 16°F | Apr 3 | Mar 31 | Mar 27 | Mar 24 | Mar 21 | Mar 19 | Mar 16 | Mar 12 | Mar 7 |
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 20 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 5 | Oct 9 | Oct 13 |
| 32°F | Sep 27 | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 24 |
| 28°F | Oct 5 | Oct 11 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 4 |
| 24°F | Oct 17 | Oct 23 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 16 |
| 20°F | Oct 31 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 27 |
| 16°F | Nov 6 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 27 | Dec 1 | Dec 7 |
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 | 156 | 150 | 146 | 142 | 138 | 134 | 130 | 125 | 117 |
| 32°F | 180 | 173 | 167 | 163 | 158 | 154 | 150 | 144 | 135 |
| 28°F | 205 | 198 | 192 | 187 | 182 | 177 | 173 | 168 | 161 |
| 24°F | 227 | 220 | 214 | 211 | 206 | 203 | 199 | 193 | 185 |
| 20°F | 249 | 241 | 235 | 231 | 226 | 223 | 219 | 213 | 207 |
| 16°F | 266 | 259 | 254 | 249 | 245 | 241 | 236 | 231 | 225 |
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
- 7,673
- Cooling degree days, base 65°F
- 483
- Growing degree days, base 40°F
- 4,317
- Growing degree days, base 45°F
- 3,299
- Growing degree days, base 50°F
- 2,404
- Growing degree days, base 55°F
- 1,632
- Growing degree days, base 60°F
- 984
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,489 | 0 | 0 |
| February | 1,247 | 0 | 0 |
| March | 1,028 | 1 | 10 |
| April | 621 | 2 | 51 |
| May | 294 | 27 | 233 |
| June | 70 | 101 | 482 |
| July | 16 | 173 | 622 |
| August | 29 | 130 | 566 |
| September | 172 | 47 | 337 |
| October | 520 | 4 | 93 |
| November | 896 | 0 | 9 |
| December | 1,291 | 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 6.6 km from Dodge County. 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 USC00473756 (Horicon Wwtp). Public domain.