Hines Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Burns Muni AP. 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 June 11 and the first fall freeze around September 6, a growing season of about 85 days.
- Median at 32°F
- last June 11, first September 6
- Median at 28°F
- last May 20, first September 19
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 | – | – | – | – | – | – | – | – | – |
| 32°F | Jun 28 | Jun 23 | Jun 19 | Jun 15 | Jun 11 | Jun 8 | Jun 4 | May 30 | May 21 |
| 28°F | Jun 14 | Jun 6 | Jun 1 | May 26 | May 20 | May 16 | May 12 | May 7 | May 2 |
| 24°F | May 25 | May 14 | May 8 | May 4 | May 1 | Apr 28 | Apr 25 | Apr 21 | Apr 15 |
| 20°F | May 6 | Apr 30 | Apr 25 | Apr 20 | Apr 15 | Apr 9 | Apr 2 | Mar 25 | Mar 15 |
| 16°F | Apr 20 | Apr 8 | Mar 31 | Mar 23 | Mar 15 | Mar 11 | Mar 6 | Mar 2 | Feb 23 |
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 | – | – | – | – | – | – | – | – | – |
| 32°F | Aug 21 | Aug 28 | Sep 1 | Sep 3 | Sep 6 | Sep 9 | Sep 13 | Sep 16 | Sep 20 |
| 28°F | Sep 3 | Sep 9 | Sep 13 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 29 | Oct 3 |
| 24°F | Sep 17 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 11 | Oct 16 |
| 20°F | Sep 30 | Oct 3 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 21 | Oct 26 | Nov 2 |
| 16°F | Oct 8 | Oct 14 | Oct 17 | Oct 22 | Oct 26 | Oct 31 | Nov 3 | Nov 10 | Nov 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 | 79 | 71 | 66 | 61 | 57 | 52 | 47 | 41 | 34 |
| 32°F | 111 | 100 | 94 | 89 | 85 | 80 | 74 | 68 | 59 |
| 28°F | 146 | 137 | 131 | 125 | 120 | 114 | 108 | 100 | 90 |
| 24°F | 176 | 167 | 162 | 157 | 152 | 147 | 142 | 135 | 124 |
| 20°F | 216 | 203 | 195 | 187 | 181 | 176 | 170 | 163 | 156 |
| 16°F | 255 | 242 | 235 | 227 | 221 | 214 | 206 | 196 | 184 |
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
- 7,214
- Cooling degree days, base 65°F
- 302
- Growing degree days, base 40°F
- 3,707
- Growing degree days, base 45°F
- 2,686
- Growing degree days, base 50°F
- 1,855
- Growing degree days, base 55°F
- 1,189
- Growing degree days, base 60°F
- 668
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,194 | 0 | 0 |
| February | 953 | 0 | 0 |
| March | 815 | 0 | 2 |
| April | 632 | 0 | 22 |
| May | 383 | 4 | 145 |
| June | 190 | 30 | 300 |
| July | 37 | 150 | 578 |
| August | 55 | 102 | 512 |
| September | 232 | 16 | 253 |
| October | 603 | 0 | 43 |
| November | 909 | 0 | 2 |
| December | 1,210 | 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 10.6 km from Hines. 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 USW00094185 (Burns Muni AP). Public domain.