Republic Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Clarksburg. 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 June 5 and the first fall freeze around September 10, a growing season of about 96 days.
- Median at 32°F
- last June 5, first September 10
- Median at 28°F
- last May 23, first September 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 | – | – | – | – | – | – | – | – | – |
| 32°F | Jun 24 | Jun 17 | Jun 12 | Jun 8 | Jun 5 | Jun 2 | May 31 | May 27 | May 23 |
| 28°F | Jun 6 | Jun 1 | May 29 | May 26 | May 23 | May 20 | May 16 | May 13 | May 8 |
| 24°F | May 26 | May 20 | May 16 | May 13 | May 9 | May 6 | May 3 | Apr 30 | Apr 27 |
| 20°F | May 13 | May 7 | May 3 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 18 | Apr 13 |
| 16°F | May 1 | Apr 27 | Apr 24 | Apr 21 | Apr 17 | Apr 15 | Apr 12 | Apr 8 | Apr 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 | – | – | – | – | – | – | – | – | – |
| 32°F | Aug 23 | Aug 31 | Sep 3 | Sep 6 | Sep 10 | Sep 14 | Sep 19 | Sep 24 | Oct 1 |
| 28°F | Sep 7 | Sep 14 | Sep 19 | Sep 23 | Sep 28 | Oct 1 | Oct 3 | Oct 7 | Oct 13 |
| 24°F | Sep 24 | Sep 29 | Oct 3 | Oct 7 | Oct 11 | Oct 14 | Oct 18 | Oct 22 | Oct 27 |
| 20°F | Oct 9 | Oct 13 | Oct 18 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 24 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 12 | Nov 16 | Nov 20 |
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 | 89 | 81 | 74 | 68 | 63 | 57 | 51 | 45 | 37 |
| 32°F | 118 | 111 | 105 | 100 | 96 | 91 | 86 | 79 | 69 |
| 28°F | 149 | 141 | 135 | 131 | 127 | 122 | 117 | 111 | 103 |
| 24°F | 175 | 167 | 163 | 158 | 154 | 149 | 145 | 139 | 131 |
| 20°F | 198 | 190 | 186 | 181 | 177 | 173 | 169 | 163 | 155 |
| 16°F | 220 | 212 | 207 | 203 | 200 | 196 | 192 | 187 | 179 |
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
- 9,812
- Cooling degree days, base 65°F
- 141
- Growing degree days, base 40°F
- 2,975
- Growing degree days, base 45°F
- 2,135
- Growing degree days, base 50°F
- 1,415
- Growing degree days, base 55°F
- 826
- Growing degree days, base 60°F
- 398
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,647 | 0 | 0 |
| February | 1,463 | 0 | 0 |
| March | 1,327 | 0 | 3 |
| April | 869 | 0 | 8 |
| May | 490 | 5 | 105 |
| June | 196 | 27 | 292 |
| July | 101 | 58 | 422 |
| August | 135 | 36 | 367 |
| September | 324 | 15 | 186 |
| October | 712 | 1 | 32 |
| November | 1,080 | 0 | 0 |
| December | 1,468 | 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 14.3 km from Republic. 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 USC00201435 (Clarksburg). Public domain.