Boydton Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Chase City. 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 6 and the first fall freeze around November 1, a growing season of about 209 days.
- Median at 36°F
- last April 20, first October 24
- Median at 32°F
- last April 6, first November 1
- Median at 28°F
- last March 25, first November 11
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 8 | May 2 | Apr 26 | Apr 23 | Apr 20 | Apr 17 | Apr 13 | Apr 10 | Apr 4 |
| 32°F | Apr 21 | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 28 | Mar 21 |
| 28°F | Apr 8 | Apr 4 | Mar 31 | Mar 28 | Mar 25 | Mar 21 | Mar 17 | Mar 12 | Mar 3 |
| 24°F | Mar 30 | Mar 24 | Mar 18 | Mar 13 | Mar 9 | Mar 5 | Feb 28 | Feb 24 | Feb 14 |
| 20°F | Mar 18 | Mar 10 | Mar 3 | Feb 28 | Feb 23 | Feb 16 | Feb 9 | Feb 2 | Jan 23 |
| 16°F | Mar 3 | Feb 22 | Feb 11 | Feb 3 | Jan 31 | Jan 26 | Jan 19 | Jan 13 | Jan 3 |
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 10 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 4 |
| 32°F | Oct 19 | Oct 24 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 16 |
| 28°F | Oct 29 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 19 | Nov 25 | Dec 2 |
| 24°F | Nov 9 | Nov 13 | Nov 18 | Nov 24 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 21 |
| 20°F | Nov 24 | Dec 1 | Dec 6 | Dec 10 | Dec 17 | Dec 23 | Dec 30 | Jan 5 | Jan 15 |
| 16°F | Dec 7 | Dec 14 | Dec 21 | Dec 28 | Jan 1 | Jan 8 | Jan 14 | Jan 20 | Jan 31 |
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 | 205 | 199 | 194 | 191 | 187 | 183 | 178 | 173 | 167 |
| 32°F | 229 | 222 | 217 | 213 | 209 | 205 | 200 | 196 | 189 |
| 28°F | 263 | 251 | 244 | 238 | 233 | 229 | 223 | 218 | 211 |
| 24°F | 293 | 282 | 274 | 269 | 264 | 259 | 253 | 246 | 237 |
| 20°F | 331 | 319 | 309 | 303 | 296 | 289 | 283 | 275 | 265 |
| 16°F | 365 | 353 | 345 | 337 | 332 | 326 | 316 | 305 | 295 |
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
- 88% 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
- 3,752
- Cooling degree days, base 65°F
- 1,432
- Growing degree days, base 40°F
- 7,126
- Growing degree days, base 45°F
- 5,656
- Growing degree days, base 50°F
- 4,354
- Growing degree days, base 55°F
- 3,217
- Growing degree days, base 60°F
- 2,246
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 798 | 0 | 17 |
| February | 651 | 0 | 25 |
| March | 523 | 4 | 92 |
| April | 247 | 30 | 259 |
| May | 81 | 117 | 502 |
| June | 7 | 288 | 731 |
| July | 0 | 414 | 879 |
| August | 1 | 362 | 826 |
| September | 27 | 185 | 608 |
| October | 218 | 31 | 293 |
| November | 478 | 2 | 93 |
| December | 720 | 1 | 31 |
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 14.5 km from Boydton. 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 USC00441606 (Chase City). Public domain.