Brooksville Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Augusta 2. 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 11 and the first fall freeze around October 30, a growing season of about 200 days.
- Median at 36°F
- last April 24, first October 18
- Median at 32°F
- last April 11, first October 30
- Median at 28°F
- last March 31, first November 9
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 12 | May 6 | May 2 | Apr 29 | Apr 24 | Apr 21 | Apr 18 | Apr 14 | Apr 9 |
| 32°F | May 2 | Apr 22 | Apr 18 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 30 |
| 28°F | Apr 15 | Apr 10 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 19 | Mar 13 |
| 24°F | Apr 4 | Mar 31 | Mar 26 | Mar 22 | Mar 19 | Mar 16 | Mar 11 | Mar 6 | Feb 28 |
| 20°F | Mar 25 | Mar 19 | Mar 15 | Mar 11 | Mar 7 | Mar 3 | Feb 28 | Feb 23 | Feb 14 |
| 16°F | Mar 16 | Mar 8 | Mar 4 | Feb 28 | Feb 25 | Feb 19 | Feb 12 | Feb 6 | Jan 30 |
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 5 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 26 | Oct 31 |
| 32°F | Oct 16 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 2 | Nov 6 | Nov 10 |
| 28°F | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 25 |
| 24°F | Nov 6 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 25 | Nov 29 | Dec 3 | Dec 9 |
| 20°F | Nov 15 | Nov 21 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 12 | Dec 19 | Dec 27 |
| 16°F | Nov 27 | Dec 4 | Dec 9 | Dec 14 | Dec 19 | Dec 24 | Dec 29 | Jan 2 | Jan 11 |
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 | 197 | 189 | 185 | 180 | 176 | 172 | 167 | 162 | 154 |
| 32°F | 219 | 212 | 208 | 204 | 200 | 196 | 190 | 185 | 177 |
| 28°F | 245 | 238 | 232 | 227 | 223 | 218 | 214 | 208 | 201 |
| 24°F | 273 | 265 | 258 | 252 | 247 | 242 | 237 | 231 | 224 |
| 20°F | 300 | 291 | 285 | 279 | 275 | 268 | 262 | 255 | 245 |
| 16°F | 326 | 316 | 307 | 302 | 297 | 292 | 286 | 280 | 270 |
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
- 4,700
- Cooling degree days, base 65°F
- 1,148
- Growing degree days, base 40°F
- 6,299
- Growing degree days, base 45°F
- 4,952
- Growing degree days, base 50°F
- 3,775
- Growing degree days, base 55°F
- 2,759
- Growing degree days, base 60°F
- 1,886
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,016 | 0 | 3 |
| February | 827 | 0 | 5 |
| March | 630 | 0 | 49 |
| April | 314 | 14 | 202 |
| May | 101 | 98 | 465 |
| June | 4 | 226 | 672 |
| July | 0 | 344 | 809 |
| August | 2 | 299 | 762 |
| September | 57 | 144 | 537 |
| October | 282 | 23 | 231 |
| November | 590 | 0 | 37 |
| December | 877 | 0 | 5 |
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 10.7 km from Brooksville. 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 USC00150290 (Augusta 2). Public domain.