Floodwood Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Floodwood 3 Ne. 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 29 and the first fall freeze around September 18, a growing season of about 111 days.
- Median at 32°F
- last May 29, first September 18
- Median at 28°F
- last May 16, first September 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 | – | – | – | – | – | – | – | – | – |
| 32°F | Jun 13 | Jun 7 | Jun 3 | May 31 | May 29 | May 26 | May 23 | May 19 | May 14 |
| 28°F | May 31 | May 27 | May 23 | May 19 | May 16 | May 12 | May 8 | May 3 | Apr 30 |
| 24°F | May 20 | May 14 | May 9 | May 5 | May 2 | Apr 30 | Apr 28 | Apr 24 | Apr 19 |
| 20°F | May 7 | May 1 | Apr 28 | Apr 25 | Apr 23 | Apr 20 | Apr 17 | Apr 13 | Apr 9 |
| 16°F | Apr 26 | Apr 21 | Apr 18 | Apr 14 | Apr 11 | Apr 8 | Apr 5 | Apr 3 | Mar 31 |
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 | – | – | – | – | – | – | – | – | – |
| 32°F | Sep 1 | Sep 6 | Sep 11 | Sep 15 | Sep 18 | Sep 21 | Sep 24 | Sep 28 | Oct 2 |
| 28°F | Sep 12 | Sep 18 | Sep 23 | Sep 26 | Sep 29 | Oct 2 | Oct 4 | Oct 8 | Oct 13 |
| 24°F | Sep 24 | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 21 | Oct 27 |
| 20°F | Oct 6 | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 18 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 12 | Nov 17 |
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 | 108 | 101 | 95 | 90 | 85 | 80 | 75 | 68 | 59 |
| 32°F | 131 | 124 | 118 | 114 | 111 | 106 | 102 | 97 | 90 |
| 28°F | 155 | 148 | 143 | 137 | 133 | 129 | 125 | 120 | 112 |
| 24°F | 180 | 172 | 167 | 162 | 158 | 153 | 149 | 144 | 135 |
| 20°F | 205 | 197 | 191 | 186 | 182 | 178 | 173 | 168 | 159 |
| 16°F | 224 | 217 | 212 | 208 | 205 | 201 | 196 | 191 | 182 |
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
- 9,833
- Cooling degree days, base 65°F
- 181
- Growing degree days, base 40°F
- 3,210
- Growing degree days, base 45°F
- 2,337
- Growing degree days, base 50°F
- 1,587
- Growing degree days, base 55°F
- 964
- Growing degree days, base 60°F
- 482
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,795 | 0 | 0 |
| February | 1,499 | 0 | 0 |
| March | 1,251 | 0 | 2 |
| April | 797 | 0 | 17 |
| May | 437 | 8 | 129 |
| June | 167 | 29 | 319 |
| July | 75 | 77 | 467 |
| August | 103 | 52 | 415 |
| September | 307 | 15 | 200 |
| October | 707 | 1 | 37 |
| November | 1,122 | 0 | 2 |
| December | 1,572 | 0 | 0 |
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 6.2 km from Floodwood. 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 USC00212842 (Floodwood 3 Ne). Public domain.