Garner Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Britt 3E. 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 29 and the first fall freeze around October 7, a growing season of about 161 days.
- Median at 36°F
- last May 7, first September 30
- Median at 32°F
- last April 29, first October 7
- Median at 28°F
- last April 18, first October 17
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 20 | May 15 | May 12 | May 9 | May 7 | May 5 | May 2 | Apr 30 | Apr 24 |
| 32°F | May 10 | May 5 | May 3 | May 1 | Apr 29 | Apr 25 | Apr 22 | Apr 18 | Apr 14 |
| 28°F | May 2 | Apr 27 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 8 | Apr 4 |
| 24°F | Apr 23 | Apr 19 | Apr 14 | Apr 11 | Apr 8 | Apr 6 | Apr 3 | Apr 1 | Mar 25 |
| 20°F | Apr 16 | Apr 10 | Apr 7 | Apr 4 | Apr 2 | Mar 30 | Mar 26 | Mar 20 | Mar 15 |
| 16°F | Apr 7 | Apr 3 | Mar 31 | Mar 28 | Mar 23 | Mar 19 | Mar 16 | Mar 12 | Mar 8 |
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 | Sep 16 | Sep 20 | Sep 24 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 11 |
| 32°F | Sep 24 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 9 | Oct 12 | Oct 15 | Oct 20 |
| 28°F | Oct 4 | Oct 8 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 30 |
| 24°F | Oct 13 | Oct 19 | Oct 22 | Oct 25 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 10 |
| 20°F | Oct 23 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
| 16°F | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 16 | Nov 20 | Nov 24 | Nov 30 |
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 | 161 | 155 | 151 | 147 | 143 | 140 | 136 | 131 | 125 |
| 32°F | 179 | 172 | 168 | 164 | 161 | 157 | 154 | 149 | 144 |
| 28°F | 200 | 194 | 189 | 184 | 180 | 175 | 172 | 167 | 162 |
| 24°F | 220 | 214 | 209 | 204 | 200 | 196 | 192 | 186 | 180 |
| 20°F | 238 | 231 | 225 | 221 | 217 | 213 | 208 | 203 | 197 |
| 16°F | 257 | 249 | 244 | 239 | 235 | 230 | 225 | 220 | 213 |
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
- 7,721
- Cooling degree days, base 65°F
- 650
- Growing degree days, base 40°F
- 4,634
- Growing degree days, base 45°F
- 3,609
- Growing degree days, base 50°F
- 2,691
- Growing degree days, base 55°F
- 1,888
- Growing degree days, base 60°F
- 1,204
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,550 | 0 | 0 |
| February | 1,285 | 0 | 0 |
| March | 1,026 | 0 | 9 |
| April | 591 | 3 | 63 |
| May | 245 | 39 | 285 |
| June | 38 | 153 | 566 |
| July | 8 | 231 | 688 |
| August | 22 | 157 | 600 |
| September | 156 | 61 | 366 |
| October | 517 | 7 | 105 |
| November | 932 | 0 | 10 |
| December | 1,353 | 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 11.6 km from Garner. 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 USC00130923 (Britt 3E). Public domain.