Conrad Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Conrad. 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 20 and the first fall freeze around September 19, a growing season of about 119 days.
- Median at 36°F
- last June 7, first September 7
- Median at 32°F
- last May 20, first September 19
- Median at 28°F
- last May 8, first September 30
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 | Jun 26 | Jun 19 | Jun 14 | Jun 10 | Jun 7 | Jun 4 | Jun 1 | May 29 | May 24 |
| 32°F | Jun 3 | May 30 | May 26 | May 23 | May 20 | May 18 | May 15 | May 13 | May 9 |
| 28°F | May 19 | May 15 | May 12 | May 10 | May 8 | May 5 | May 3 | Apr 30 | Apr 27 |
| 24°F | May 9 | May 5 | May 2 | Apr 30 | Apr 27 | Apr 25 | Apr 21 | Apr 16 | Apr 11 |
| 20°F | May 1 | Apr 26 | Apr 22 | Apr 19 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Mar 31 |
| 16°F | Apr 22 | Apr 16 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 27 | Mar 19 |
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 | Aug 22 | Aug 28 | Sep 2 | Sep 4 | Sep 7 | Sep 9 | Sep 12 | Sep 15 | Sep 19 |
| 32°F | Sep 4 | Sep 10 | Sep 14 | Sep 17 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Oct 2 |
| 28°F | Sep 15 | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 12 |
| 24°F | Sep 26 | Oct 1 | Oct 4 | Oct 6 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 24 |
| 20°F | Oct 3 | Oct 7 | Oct 12 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 16°F | Oct 8 | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 5 | Nov 10 |
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 | 110 | 104 | 99 | 95 | 92 | 87 | 82 | 77 | 68 |
| 32°F | 138 | 132 | 128 | 123 | 119 | 116 | 112 | 108 | 101 |
| 28°F | 163 | 156 | 151 | 148 | 144 | 141 | 137 | 132 | 126 |
| 24°F | 184 | 179 | 173 | 169 | 165 | 162 | 158 | 153 | 146 |
| 20°F | 206 | 199 | 194 | 189 | 185 | 182 | 177 | 172 | 166 |
| 16°F | 226 | 218 | 213 | 208 | 204 | 200 | 195 | 189 | 181 |
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
- 7,981
- Cooling degree days, base 65°F
- 242
- Growing degree days, base 40°F
- 3,595
- Growing degree days, base 45°F
- 2,591
- Growing degree days, base 50°F
- 1,758
- Growing degree days, base 55°F
- 1,089
- Growing degree days, base 60°F
- 580
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,313 | 0 | 0 |
| February | 1,124 | 0 | 1 |
| March | 983 | 0 | 4 |
| April | 659 | 0 | 25 |
| May | 394 | 3 | 136 |
| June | 179 | 23 | 300 |
| July | 51 | 111 | 526 |
| August | 70 | 90 | 488 |
| September | 272 | 14 | 224 |
| October | 652 | 1 | 49 |
| November | 998 | 0 | 5 |
| December | 1,288 | 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 0.5 km from Conrad. 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 USC00241974 (Conrad). Public domain.