Bushland Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Bushland 1 Wsw. 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 22 and the first fall freeze around October 21, a growing season of about 182 days.
- Median at 36°F
- last May 2, first October 13
- Median at 32°F
- last April 22, first October 21
- Median at 28°F
- last April 12, first October 31
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 11 | May 8 | May 6 | May 4 | May 2 | Apr 30 | Apr 28 | Apr 25 | Apr 20 |
| 32°F | May 3 | Apr 30 | Apr 27 | Apr 25 | Apr 22 | Apr 20 | Apr 17 | Apr 14 | Apr 10 |
| 28°F | Apr 26 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 9 | Apr 5 | Mar 31 | Mar 25 |
| 24°F | Apr 17 | Apr 10 | Apr 5 | Apr 3 | Mar 31 | Mar 28 | Mar 23 | Mar 18 | Mar 11 |
| 20°F | Apr 5 | Mar 31 | Mar 25 | Mar 21 | Mar 16 | Mar 12 | Mar 8 | Mar 4 | Feb 28 |
| 16°F | Mar 23 | Mar 15 | Mar 9 | Mar 5 | Mar 3 | Feb 28 | Feb 24 | Feb 20 | Feb 12 |
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 29 | Oct 4 | Oct 7 | Oct 11 | Oct 13 | Oct 15 | Oct 18 | Oct 20 | Oct 23 |
| 32°F | Oct 6 | Oct 12 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 1 |
| 28°F | Oct 19 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 12 |
| 24°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 13 | Nov 17 | Nov 21 |
| 20°F | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 1 |
| 16°F | Nov 9 | Nov 15 | Nov 20 | Nov 24 | Nov 27 | Nov 30 | Dec 5 | Dec 9 | Dec 16 |
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 | 180 | 174 | 171 | 167 | 164 | 161 | 158 | 153 | 146 |
| 32°F | 199 | 193 | 189 | 185 | 182 | 179 | 175 | 171 | 165 |
| 28°F | 220 | 215 | 209 | 205 | 201 | 197 | 194 | 189 | 182 |
| 24°F | 244 | 237 | 231 | 226 | 221 | 217 | 212 | 207 | 200 |
| 20°F | 268 | 260 | 254 | 249 | 244 | 240 | 235 | 229 | 220 |
| 16°F | 296 | 286 | 279 | 273 | 268 | 263 | 257 | 251 | 241 |
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
- 4,445
- Cooling degree days, base 65°F
- 1,231
- Growing degree days, base 40°F
- 6,533
- Growing degree days, base 45°F
- 5,146
- Growing degree days, base 50°F
- 3,922
- Growing degree days, base 55°F
- 2,874
- Growing degree days, base 60°F
- 1,979
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 902 | 0 | 4 |
| February | 722 | 0 | 20 |
| March | 559 | 1 | 71 |
| April | 337 | 9 | 180 |
| May | 116 | 91 | 446 |
| June | 6 | 271 | 715 |
| July | 0 | 364 | 829 |
| August | 3 | 328 | 790 |
| September | 43 | 144 | 552 |
| October | 268 | 23 | 261 |
| November | 614 | 0 | 48 |
| December | 876 | 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 1.5 km from Bushland. 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 USC00411267 (Bushland 1 Wsw). Public domain.