Old Forge Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Old Forge. 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 September 30, a growing season of about 134 days.
- Median at 36°F
- last May 31, first September 19
- Median at 32°F
- last May 18, first September 30
- Median at 28°F
- last May 5, 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 8 | Jun 4 | Jun 2 | May 31 | May 29 | May 26 | May 22 | May 17 |
| 32°F | Jun 1 | May 29 | May 25 | May 22 | May 18 | May 14 | May 11 | May 7 | May 1 |
| 28°F | May 22 | May 16 | May 12 | May 8 | May 5 | May 3 | Apr 30 | Apr 27 | Apr 23 |
| 24°F | May 10 | May 5 | May 1 | Apr 27 | Apr 24 | Apr 22 | Apr 20 | Apr 16 | Apr 11 |
| 20°F | Apr 25 | Apr 21 | Apr 19 | Apr 16 | Apr 13 | Apr 11 | Apr 8 | Apr 5 | Apr 3 |
| 16°F | Apr 18 | Apr 13 | Apr 10 | Apr 7 | Apr 6 | Apr 3 | Apr 2 | Mar 31 | Mar 28 |
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 17 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Oct 1 |
| 32°F | Sep 18 | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 4 | Oct 8 | Oct 14 |
| 28°F | Sep 27 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 21 | Oct 26 |
| 24°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 26 | Oct 30 | Nov 2 | Nov 7 |
| 20°F | Oct 18 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 13 | Nov 17 |
| 16°F | Oct 31 | Nov 3 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 28 |
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 | 115 | 110 | 106 | 102 | 97 | 90 |
| 32°F | 153 | 147 | 142 | 138 | 134 | 130 | 126 | 121 | 114 |
| 28°F | 180 | 172 | 166 | 161 | 157 | 152 | 148 | 143 | 137 |
| 24°F | 202 | 194 | 189 | 185 | 181 | 177 | 172 | 167 | 160 |
| 20°F | 221 | 214 | 210 | 207 | 203 | 200 | 195 | 190 | 183 |
| 16°F | 240 | 232 | 228 | 224 | 220 | 217 | 214 | 210 | 204 |
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
- 8,686
- Cooling degree days, base 65°F
- 170
- Growing degree days, base 40°F
- 3,396
- Growing degree days, base 45°F
- 2,470
- Growing degree days, base 50°F
- 1,673
- Growing degree days, base 55°F
- 1,002
- Growing degree days, base 60°F
- 490
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,525 | 0 | 0 |
| February | 1,326 | 0 | 0 |
| March | 1,220 | 0 | 2 |
| April | 769 | 1 | 24 |
| May | 399 | 10 | 157 |
| June | 159 | 33 | 330 |
| July | 75 | 62 | 453 |
| August | 93 | 48 | 421 |
| September | 258 | 15 | 234 |
| October | 614 | 1 | 49 |
| November | 942 | 0 | 4 |
| December | 1,307 | 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 1.2 km from Old Forge. 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 USC00306184 (Old Forge). Public domain.