Rowlesburg Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Rowlesburg 1. 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 28 and the first fall freeze around October 23, a growing season of about 179 days.
- Median at 36°F
- last May 7, first October 13
- Median at 32°F
- last April 28, first October 23
- Median at 28°F
- last April 14, first November 1
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 23 | May 18 | May 14 | May 11 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 |
| 32°F | May 15 | May 9 | May 4 | Apr 30 | Apr 28 | Apr 24 | Apr 21 | Apr 17 | Apr 12 |
| 28°F | May 3 | Apr 26 | Apr 21 | Apr 17 | Apr 14 | Apr 11 | Apr 7 | Apr 3 | Mar 30 |
| 24°F | Apr 18 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 26 | Mar 20 | Mar 15 |
| 20°F | Apr 7 | Apr 1 | Mar 29 | Mar 25 | Mar 20 | Mar 17 | Mar 13 | Mar 7 | Mar 1 |
| 16°F | Mar 30 | Mar 22 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 2 | Feb 26 | Feb 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 | Oct 2 | Oct 6 | Oct 8 | Oct 11 | Oct 13 | Oct 15 | Oct 18 | Oct 21 | Oct 25 |
| 32°F | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 4 |
| 28°F | Oct 19 | Oct 24 | Oct 27 | Oct 31 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 15 |
| 24°F | Oct 30 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 29 |
| 20°F | Nov 6 | Nov 11 | Nov 15 | Nov 19 | Nov 22 | Nov 26 | Dec 1 | Dec 5 | Dec 11 |
| 16°F | Nov 15 | Nov 22 | Nov 27 | Dec 1 | Dec 5 | Dec 9 | Dec 15 | Dec 21 | Dec 28 |
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 | 178 | 172 | 167 | 162 | 158 | 154 | 150 | 145 | 138 |
| 32°F | 197 | 191 | 187 | 183 | 179 | 175 | 171 | 166 | 159 |
| 28°F | 220 | 213 | 207 | 204 | 200 | 196 | 191 | 185 | 176 |
| 24°F | 246 | 239 | 232 | 227 | 222 | 218 | 213 | 208 | 200 |
| 20°F | 271 | 262 | 255 | 250 | 246 | 241 | 236 | 230 | 223 |
| 16°F | 298 | 288 | 281 | 275 | 269 | 264 | 258 | 253 | 243 |
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
- 5,571
- Cooling degree days, base 65°F
- 666
- Growing degree days, base 40°F
- 5,315
- Growing degree days, base 45°F
- 4,086
- Growing degree days, base 50°F
- 3,004
- Growing degree days, base 55°F
- 2,074
- Growing degree days, base 60°F
- 1,292
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,108 | 0 | 3 |
| February | 914 | 0 | 4 |
| March | 774 | 0 | 30 |
| April | 430 | 4 | 129 |
| May | 191 | 42 | 327 |
| June | 37 | 124 | 537 |
| July | 4 | 213 | 674 |
| August | 7 | 195 | 652 |
| September | 83 | 80 | 448 |
| October | 374 | 8 | 161 |
| November | 686 | 0 | 30 |
| December | 964 | 0 | 7 |
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 0.7 km from Rowlesburg. 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 USC00467785 (Rowlesburg 1). Public domain.