Jordan Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Jordan. 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 21 and the first fall freeze around September 18, a growing season of about 118 days.
- Median at 36°F
- last May 30, first September 8
- Median at 32°F
- last May 21, first September 18
- Median at 28°F
- last May 9, first September 26
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 16 | Jun 9 | Jun 5 | Jun 1 | May 30 | May 28 | May 25 | May 22 | May 18 |
| 32°F | Jun 2 | May 29 | May 26 | May 23 | May 21 | May 18 | May 16 | May 12 | May 8 |
| 28°F | May 23 | May 18 | May 15 | May 12 | May 9 | May 7 | May 3 | May 1 | Apr 26 |
| 24°F | May 12 | May 7 | May 3 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 19 | Apr 14 |
| 20°F | May 2 | Apr 28 | Apr 24 | Apr 20 | Apr 16 | Apr 13 | Apr 10 | Apr 6 | Apr 1 |
| 16°F | Apr 24 | Apr 17 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 25 | Mar 16 |
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 26 | Aug 31 | Sep 3 | Sep 5 | Sep 8 | Sep 11 | Sep 13 | Sep 16 | Sep 21 |
| 32°F | Sep 4 | Sep 9 | Sep 13 | Sep 16 | Sep 18 | Sep 20 | Sep 23 | Sep 26 | Oct 1 |
| 28°F | Sep 13 | Sep 18 | Sep 22 | Sep 24 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 9 |
| 24°F | Sep 21 | Sep 26 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 15 | Oct 20 |
| 20°F | Sep 29 | Oct 5 | Oct 8 | Oct 13 | Oct 15 | Oct 18 | Oct 22 | Oct 27 | Nov 1 |
| 16°F | Oct 7 | Oct 14 | Oct 18 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 | Nov 11 |
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 | 116 | 110 | 106 | 102 | 99 | 95 | 92 | 87 | 78 |
| 32°F | 135 | 130 | 126 | 122 | 118 | 115 | 111 | 107 | 100 |
| 28°F | 156 | 150 | 145 | 142 | 138 | 134 | 131 | 125 | 119 |
| 24°F | 178 | 171 | 166 | 162 | 157 | 154 | 150 | 145 | 139 |
| 20°F | 204 | 196 | 191 | 186 | 182 | 176 | 171 | 165 | 157 |
| 16°F | 227 | 218 | 212 | 207 | 203 | 198 | 193 | 187 | 176 |
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
- 8,253
- Cooling degree days, base 65°F
- 486
- Growing degree days, base 40°F
- 3,952
- Growing degree days, base 45°F
- 2,983
- Growing degree days, base 50°F
- 2,158
- Growing degree days, base 55°F
- 1,466
- Growing degree days, base 60°F
- 907
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,480 | 0 | 0 |
| February | 1,236 | 0 | 0 |
| March | 1,020 | 0 | 3 |
| April | 653 | 0 | 31 |
| May | 379 | 9 | 165 |
| June | 118 | 61 | 397 |
| July | 22 | 206 | 649 |
| August | 45 | 180 | 601 |
| September | 251 | 29 | 257 |
| October | 640 | 1 | 52 |
| November | 1,026 | 0 | 3 |
| December | 1,382 | 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 0.7 km from Jordan. 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 USC00244522 (Jordan). Public domain.