Burke County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Northgate 5 Ese. 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 121 days.
- Median at 36°F
- last May 29, first September 9
- Median at 32°F
- last May 20, first September 19
- Median at 28°F
- last May 11, first September 26
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 15 | Jun 7 | Jun 3 | May 31 | May 29 | May 27 | May 24 | May 22 | May 17 |
| 32°F | Jun 2 | May 29 | May 26 | May 23 | May 20 | May 18 | May 16 | May 12 | May 9 |
| 28°F | May 24 | May 20 | May 16 | May 14 | May 11 | May 9 | May 6 | May 3 | Apr 29 |
| 24°F | May 15 | May 11 | May 8 | May 5 | May 2 | Apr 30 | Apr 27 | Apr 22 | Apr 16 |
| 20°F | May 7 | May 2 | Apr 29 | Apr 25 | Apr 21 | Apr 18 | Apr 15 | Apr 11 | Apr 7 |
| 16°F | Apr 28 | Apr 22 | Apr 17 | Apr 14 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 28 |
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 25 | Aug 31 | Sep 3 | Sep 6 | Sep 9 | Sep 11 | Sep 14 | Sep 17 | Sep 20 |
| 32°F | Sep 7 | Sep 11 | Sep 14 | Sep 17 | Sep 19 | Sep 21 | Sep 23 | Sep 25 | Sep 28 |
| 28°F | Sep 14 | Sep 20 | Sep 22 | Sep 24 | Sep 26 | Sep 28 | Oct 1 | Oct 4 | Oct 8 |
| 24°F | Sep 22 | Sep 26 | Sep 29 | Oct 1 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 18 |
| 20°F | Sep 29 | Oct 3 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 16°F | Oct 9 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Nov 1 | Nov 3 |
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 | 119 | 113 | 108 | 104 | 101 | 97 | 92 | 87 | 79 |
| 32°F | 135 | 131 | 127 | 124 | 121 | 117 | 113 | 108 | 102 |
| 28°F | 154 | 149 | 145 | 140 | 137 | 134 | 130 | 126 | 120 |
| 24°F | 175 | 168 | 163 | 158 | 154 | 150 | 147 | 141 | 134 |
| 20°F | 193 | 186 | 182 | 177 | 174 | 170 | 165 | 161 | 154 |
| 16°F | 213 | 206 | 202 | 198 | 193 | 190 | 185 | 179 | 173 |
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
- 10,000
- Cooling degree days, base 65°F
- 174
- Growing degree days, base 40°F
- 3,245
- Growing degree days, base 45°F
- 2,369
- Growing degree days, base 50°F
- 1,609
- Growing degree days, base 55°F
- 974
- Growing degree days, base 60°F
- 484
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,765 | 0 | 0 |
| February | 1,509 | 0 | 0 |
| March | 1,290 | 0 | 1 |
| April | 777 | 0 | 16 |
| May | 420 | 5 | 128 |
| June | 144 | 21 | 331 |
| July | 56 | 69 | 477 |
| August | 91 | 68 | 442 |
| September | 320 | 13 | 190 |
| October | 771 | 1 | 24 |
| November | 1,220 | 0 | 1 |
| December | 1,638 | 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 32.1 km from Burke County. 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 USW00094084 (Northgate 5 Ese). Public domain.