Ekalaka Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Ekalaka. 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 20 and the first fall freeze around September 23, a growing season of about 126 days.
- Median at 36°F
- last May 31, first September 13
- Median at 32°F
- last May 20, first September 23
- Median at 28°F
- last May 10, first October 2
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 21 | Jun 14 | Jun 8 | Jun 4 | May 31 | May 29 | May 26 | May 24 | May 19 |
| 32°F | Jun 1 | May 28 | May 25 | May 23 | May 20 | May 17 | May 14 | May 11 | May 7 |
| 28°F | May 23 | May 18 | May 15 | May 13 | May 10 | May 7 | May 4 | May 1 | Apr 27 |
| 24°F | May 14 | May 9 | May 5 | May 2 | Apr 29 | Apr 27 | Apr 23 | Apr 19 | Apr 13 |
| 20°F | May 4 | Apr 29 | Apr 25 | Apr 22 | Apr 18 | Apr 14 | Apr 11 | Apr 6 | Mar 31 |
| 16°F | Apr 22 | Apr 18 | Apr 14 | Apr 10 | Apr 7 | Apr 4 | Mar 31 | Mar 26 | 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 | Aug 28 | Sep 2 | Sep 7 | Sep 10 | Sep 13 | Sep 16 | Sep 20 | Sep 23 | Sep 28 |
| 32°F | Sep 7 | Sep 12 | Sep 17 | Sep 21 | Sep 23 | Sep 26 | Sep 29 | Oct 2 | Oct 7 |
| 28°F | Sep 17 | Sep 22 | Sep 26 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 17 |
| 24°F | Sep 25 | Oct 1 | Oct 4 | Oct 8 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 25 |
| 20°F | Oct 3 | Oct 10 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 26 | Oct 29 | Nov 4 |
| 16°F | Oct 13 | Oct 18 | Oct 22 | Oct 25 | Oct 28 | Nov 1 | Nov 4 | 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 | 123 | 116 | 111 | 107 | 102 | 97 | 93 | 87 | 79 |
| 32°F | 146 | 139 | 134 | 130 | 126 | 122 | 118 | 113 | 105 |
| 28°F | 164 | 158 | 153 | 149 | 145 | 142 | 137 | 133 | 127 |
| 24°F | 187 | 179 | 174 | 169 | 165 | 160 | 155 | 149 | 142 |
| 20°F | 207 | 200 | 194 | 190 | 185 | 181 | 176 | 170 | 163 |
| 16°F | 230 | 220 | 214 | 209 | 204 | 201 | 195 | 190 | 181 |
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
- 7,678
- Cooling degree days, base 65°F
- 537
- Growing degree days, base 40°F
- 4,194
- Growing degree days, base 45°F
- 3,178
- Growing degree days, base 50°F
- 2,308
- Growing degree days, base 55°F
- 1,580
- Growing degree days, base 60°F
- 986
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,344 | 0 | 0 |
| February | 1,147 | 0 | 0 |
| March | 958 | 0 | 9 |
| April | 638 | 1 | 43 |
| May | 362 | 9 | 174 |
| June | 120 | 66 | 399 |
| July | 23 | 215 | 657 |
| August | 38 | 193 | 621 |
| September | 200 | 51 | 324 |
| October | 598 | 3 | 74 |
| November | 968 | 0 | 6 |
| December | 1,283 | 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 0.5 km from Ekalaka. 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 USC00242689 (Ekalaka). Public domain.