Elk County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Ridgway. 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 13 and the first fall freeze around October 11, a growing season of about 150 days.
- Median at 36°F
- last May 25, first September 29
- Median at 32°F
- last May 13, first October 11
- Median at 28°F
- last May 1, first October 25
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 7 | Jun 2 | May 31 | May 28 | May 25 | May 22 | May 18 | May 13 | May 8 |
| 32°F | May 28 | May 24 | May 20 | May 18 | May 13 | May 10 | May 5 | May 1 | Apr 26 |
| 28°F | May 19 | May 13 | May 8 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 21 | Apr 17 |
| 24°F | May 8 | May 1 | Apr 25 | Apr 21 | Apr 18 | Apr 15 | Apr 11 | Apr 7 | Apr 2 |
| 20°F | Apr 17 | Apr 13 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 19 |
| 16°F | Apr 4 | Mar 31 | Mar 29 | Mar 26 | Mar 23 | Mar 19 | Mar 17 | Mar 13 | Mar 8 |
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 15 | Sep 20 | Sep 24 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 7 | Oct 11 |
| 32°F | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 21 | Oct 26 |
| 28°F | Oct 9 | Oct 14 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 7 |
| 24°F | Oct 22 | Oct 28 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 19 |
| 20°F | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 19 | Nov 23 | Nov 27 | Dec 2 |
| 16°F | Nov 10 | Nov 16 | Nov 20 | Nov 23 | Nov 28 | Dec 1 | Dec 4 | Dec 9 | Dec 18 |
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 | 148 | 141 | 136 | 132 | 127 | 123 | 119 | 115 | 108 |
| 32°F | 174 | 166 | 159 | 155 | 150 | 146 | 141 | 136 | 127 |
| 28°F | 197 | 189 | 184 | 180 | 175 | 171 | 167 | 161 | 152 |
| 24°F | 222 | 216 | 210 | 206 | 201 | 196 | 190 | 184 | 177 |
| 20°F | 249 | 241 | 236 | 232 | 228 | 224 | 219 | 214 | 207 |
| 16°F | 271 | 264 | 258 | 253 | 248 | 243 | 238 | 233 | 226 |
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
- 6,730
- Cooling degree days, base 65°F
- 406
- Growing degree days, base 40°F
- 4,413
- Growing degree days, base 45°F
- 3,315
- Growing degree days, base 50°F
- 2,364
- Growing degree days, base 55°F
- 1,554
- Growing degree days, base 60°F
- 893
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,241 | 0 | 2 |
| February | 1,078 | 0 | 1 |
| March | 952 | 0 | 11 |
| April | 574 | 1 | 62 |
| May | 282 | 25 | 241 |
| June | 81 | 78 | 448 |
| July | 24 | 143 | 584 |
| August | 32 | 116 | 549 |
| September | 154 | 39 | 342 |
| October | 473 | 5 | 103 |
| November | 771 | 0 | 16 |
| December | 1,069 | 0 | 3 |
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 8.4 km from Elk County. 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 USC00367477 (Ridgway). Public domain.