Kenmare Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Kenmare 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 May 15 and the first fall freeze around September 23, a growing season of about 129 days.
- Median at 36°F
- last May 24, first September 14
- Median at 32°F
- last May 15, first September 23
- Median at 28°F
- last May 5, first October 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 | Jun 5 | Jun 1 | May 29 | May 26 | May 24 | May 22 | May 19 | May 16 | May 12 |
| 32°F | May 28 | May 23 | May 20 | May 17 | May 15 | May 12 | May 9 | May 6 | May 3 |
| 28°F | May 19 | May 14 | May 10 | May 7 | May 5 | May 3 | May 1 | Apr 28 | Apr 22 |
| 24°F | May 9 | May 5 | May 3 | Apr 30 | Apr 28 | Apr 25 | Apr 21 | Apr 18 | Apr 13 |
| 20°F | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 10 | Apr 5 |
| 16°F | Apr 26 | Apr 20 | Apr 16 | Apr 14 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | 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 1 | Sep 5 | Sep 9 | Sep 12 | Sep 14 | Sep 16 | Sep 19 | Sep 22 | Sep 25 |
| 32°F | Sep 10 | Sep 14 | Sep 17 | Sep 20 | Sep 23 | Sep 25 | Sep 27 | Sep 30 | Oct 4 |
| 28°F | Sep 18 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 14 |
| 24°F | Sep 25 | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 25 |
| 20°F | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Oct 29 | Nov 2 |
| 16°F | Oct 11 | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Oct 31 | Nov 3 | Nov 8 | Nov 13 |
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 | 129 | 123 | 119 | 116 | 112 | 108 | 104 | 100 | 93 |
| 32°F | 146 | 140 | 136 | 132 | 129 | 126 | 123 | 118 | 112 |
| 28°F | 167 | 160 | 156 | 151 | 148 | 144 | 140 | 135 | 129 |
| 24°F | 185 | 178 | 173 | 169 | 165 | 161 | 156 | 152 | 145 |
| 20°F | 204 | 197 | 191 | 188 | 183 | 179 | 175 | 170 | 164 |
| 16°F | 220 | 212 | 208 | 204 | 200 | 196 | 191 | 187 | 180 |
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
- 9,533
- Cooling degree days, base 65°F
- 316
- Growing degree days, base 40°F
- 3,576
- Growing degree days, base 45°F
- 2,682
- Growing degree days, base 50°F
- 1,897
- Growing degree days, base 55°F
- 1,229
- Growing degree days, base 60°F
- 695
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,717 | 0 | 0 |
| February | 1,452 | 0 | 0 |
| March | 1,237 | 0 | 2 |
| April | 754 | 0 | 27 |
| May | 380 | 10 | 170 |
| June | 121 | 51 | 383 |
| July | 41 | 124 | 549 |
| August | 67 | 109 | 508 |
| September | 288 | 21 | 223 |
| October | 731 | 1 | 35 |
| November | 1,167 | 0 | 2 |
| December | 1,578 | 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 Kenmare. 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 USC00324646 (Kenmare 1 Wsw). Public domain.