Blanding Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Blanding. 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 28 and the first fall freeze around October 21, a growing season of about 174 days.
- Median at 36°F
- last May 11, first October 10
- Median at 32°F
- last April 28, first October 21
- Median at 28°F
- last April 14, first November 1
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 28 | May 21 | May 17 | May 14 | May 11 | May 7 | May 3 | Apr 30 | Apr 26 |
| 32°F | May 16 | May 8 | May 3 | Apr 30 | Apr 28 | Apr 25 | Apr 21 | Apr 18 | Apr 13 |
| 28°F | May 1 | Apr 25 | Apr 21 | Apr 17 | Apr 14 | Apr 11 | Apr 7 | Apr 3 | Mar 24 |
| 24°F | Apr 16 | Apr 11 | Apr 6 | Apr 2 | Mar 28 | Mar 20 | Mar 13 | Mar 7 | Mar 2 |
| 20°F | Mar 30 | Mar 20 | Mar 13 | Mar 7 | Mar 2 | Feb 26 | Feb 22 | Feb 17 | Feb 12 |
| 16°F | Mar 8 | Mar 1 | Feb 25 | Feb 20 | Feb 16 | Feb 12 | Feb 7 | Feb 2 | Jan 22 |
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 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 24 |
| 32°F | Oct 6 | Oct 10 | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 28 | Nov 1 | Nov 6 |
| 28°F | Oct 16 | Oct 21 | Oct 24 | Oct 28 | Nov 1 | Nov 4 | Nov 8 | Nov 12 | Nov 17 |
| 24°F | Oct 24 | Oct 31 | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 26 |
| 20°F | Nov 5 | Nov 11 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 27 | Dec 1 | Dec 7 |
| 16°F | Nov 15 | Nov 21 | Nov 26 | Nov 29 | Dec 3 | Dec 6 | Dec 10 | Dec 14 | Dec 20 |
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 | 173 | 165 | 160 | 155 | 151 | 147 | 143 | 138 | 128 |
| 32°F | 197 | 189 | 183 | 179 | 174 | 169 | 166 | 159 | 150 |
| 28°F | 224 | 216 | 210 | 205 | 201 | 196 | 190 | 184 | 177 |
| 24°F | 258 | 248 | 240 | 233 | 228 | 223 | 216 | 210 | 203 |
| 20°F | 289 | 279 | 271 | 265 | 260 | 254 | 248 | 239 | 227 |
| 16°F | 319 | 309 | 301 | 295 | 289 | 284 | 277 | 270 | 263 |
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
- 5,450
- Cooling degree days, base 65°F
- 877
- Growing degree days, base 40°F
- 5,422
- Growing degree days, base 45°F
- 4,216
- Growing degree days, base 50°F
- 3,166
- Growing degree days, base 55°F
- 2,264
- Growing degree days, base 60°F
- 1,505
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,056 | 0 | 0 |
| February | 827 | 0 | 1 |
| March | 665 | 0 | 20 |
| April | 453 | 1 | 92 |
| May | 206 | 30 | 309 |
| June | 27 | 181 | 605 |
| July | 1 | 325 | 789 |
| August | 3 | 255 | 718 |
| September | 69 | 83 | 467 |
| October | 370 | 2 | 154 |
| November | 728 | 0 | 13 |
| December | 1,048 | 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 1.3 km from Blanding. 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 USC00420738 (Blanding). Public domain.