Alfred Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Alfred. 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 18 and the first fall freeze around October 1, a growing season of about 135 days.
- Median at 36°F
- last May 31, first September 19
- Median at 32°F
- last May 18, first October 1
- Median at 28°F
- last May 6, first October 10
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 14 | Jun 9 | Jun 4 | Jun 2 | May 31 | May 28 | May 25 | May 21 | May 14 |
| 32°F | Jun 1 | May 28 | May 25 | May 21 | May 18 | May 14 | May 10 | May 6 | May 1 |
| 28°F | May 22 | May 16 | May 12 | May 9 | May 6 | May 3 | Apr 30 | Apr 26 | Apr 22 |
| 24°F | May 11 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 10 |
| 20°F | May 1 | Apr 22 | Apr 18 | Apr 16 | Apr 13 | Apr 10 | Apr 7 | Apr 4 | Mar 31 |
| 16°F | Apr 15 | Apr 11 | Apr 7 | Apr 5 | Apr 3 | Apr 1 | Mar 29 | Mar 24 | Mar 19 |
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 3 | Sep 9 | Sep 13 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Oct 1 |
| 32°F | Sep 17 | Sep 22 | Sep 25 | Sep 27 | Oct 1 | Oct 2 | Oct 5 | Oct 7 | Oct 13 |
| 28°F | Sep 25 | Oct 1 | Oct 3 | Oct 6 | Oct 10 | Oct 13 | Oct 18 | Oct 22 | Oct 28 |
| 24°F | Oct 5 | Oct 12 | Oct 18 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 9 |
| 20°F | Oct 21 | Oct 28 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 22 |
| 16°F | Nov 2 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 24 | Nov 28 | Dec 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 | 131 | 124 | 119 | 114 | 109 | 105 | 100 | 95 | 88 |
| 32°F | 155 | 149 | 143 | 138 | 135 | 131 | 126 | 121 | 113 |
| 28°F | 177 | 171 | 166 | 161 | 158 | 154 | 150 | 144 | 137 |
| 24°F | 203 | 197 | 191 | 187 | 182 | 178 | 173 | 166 | 159 |
| 20°F | 228 | 220 | 215 | 211 | 207 | 203 | 198 | 191 | 183 |
| 16°F | 250 | 242 | 238 | 233 | 229 | 225 | 220 | 215 | 208 |
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
- 7,502
- Cooling degree days, base 65°F
- 296
- Growing degree days, base 40°F
- 3,940
- Growing degree days, base 45°F
- 2,921
- Growing degree days, base 50°F
- 2,033
- Growing degree days, base 55°F
- 1,288
- Growing degree days, base 60°F
- 698
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,339 | 0 | 0 |
| February | 1,159 | 0 | 1 |
| March | 1,037 | 0 | 8 |
| April | 658 | 1 | 46 |
| May | 331 | 19 | 203 |
| June | 112 | 61 | 401 |
| July | 42 | 111 | 535 |
| August | 64 | 79 | 481 |
| September | 221 | 22 | 266 |
| October | 539 | 2 | 79 |
| November | 851 | 0 | 13 |
| December | 1,150 | 0 | 2 |
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 3.5 km from Alfred. 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 USC00300085 (Alfred). Public domain.