Vaiden Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Winona 5 E. 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 7 and the first fall freeze around October 29, a growing season of about 203 days.
- Median at 36°F
- last April 19, first October 21
- Median at 32°F
- last April 7, first October 29
- Median at 28°F
- last March 26, first November 7
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 3 | Apr 30 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 9 | Apr 4 |
| 32°F | Apr 24 | Apr 17 | Apr 14 | Apr 10 | Apr 7 | Apr 4 | Mar 31 | Mar 28 | Mar 22 |
| 28°F | Apr 11 | Apr 5 | Apr 1 | Mar 30 | Mar 26 | Mar 21 | Mar 18 | Mar 13 | Mar 5 |
| 24°F | Mar 30 | Mar 22 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 1 | Feb 25 | Feb 18 |
| 20°F | Mar 14 | Mar 8 | Mar 3 | Feb 28 | Feb 23 | Feb 18 | Feb 12 | Feb 5 | Jan 28 |
| 16°F | Mar 6 | Feb 28 | Feb 19 | Feb 12 | Feb 5 | Jan 31 | Jan 26 | Jan 17 | Jan 5 |
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 8 | Oct 11 | Oct 15 | Oct 17 | Oct 21 | Oct 23 | Oct 25 | Oct 28 | Nov 1 |
| 32°F | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Oct 31 | Nov 2 | Nov 5 | Nov 11 |
| 28°F | Oct 25 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 20 | Nov 27 |
| 24°F | Nov 3 | Nov 8 | Nov 12 | Nov 17 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 10 |
| 20°F | Nov 11 | Nov 22 | Nov 29 | Dec 2 | Dec 6 | Dec 12 | Dec 19 | Dec 30 | Jan 6 |
| 16°F | Nov 29 | Dec 7 | Dec 15 | Dec 24 | Dec 31 | Jan 3 | Jan 8 | Jan 15 | Jan 27 |
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 | 203 | 196 | 191 | 187 | 183 | 179 | 175 | 171 | 164 |
| 32°F | 225 | 218 | 212 | 207 | 203 | 199 | 195 | 190 | 184 |
| 28°F | 254 | 244 | 238 | 232 | 227 | 222 | 216 | 211 | 204 |
| 24°F | 285 | 275 | 266 | 261 | 256 | 251 | 246 | 238 | 230 |
| 20°F | 324 | 311 | 302 | 295 | 287 | 280 | 273 | 265 | 254 |
| 16°F | 360 | 344 | 335 | 329 | 322 | 314 | 306 | 299 | 285 |
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
- 91% 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
- 3,305
- Cooling degree days, base 65°F
- 1,603
- Growing degree days, base 40°F
- 7,703
- Growing degree days, base 45°F
- 6,175
- Growing degree days, base 50°F
- 4,798
- Growing degree days, base 55°F
- 3,572
- Growing degree days, base 60°F
- 2,504
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 748 | 1 | 39 |
| February | 577 | 1 | 54 |
| March | 412 | 7 | 154 |
| April | 203 | 34 | 300 |
| May | 51 | 137 | 551 |
| June | 2 | 311 | 759 |
| July | 0 | 411 | 876 |
| August | 0 | 397 | 862 |
| September | 17 | 239 | 672 |
| October | 176 | 58 | 363 |
| November | 453 | 6 | 116 |
| December | 667 | 3 | 54 |
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 20.1 km from Vaiden. 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 USC00229743 (Winona 5 E). Public domain.