Hood River County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Parkdale 1 Nne. 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 3, a growing season of about 142 days.
- Median at 36°F
- last June 8, first September 15
- Median at 32°F
- last May 13, first October 3
- Median at 28°F
- last April 21, first October 20
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 | Jul 2 | Jun 25 | Jun 18 | Jun 13 | Jun 8 | Jun 4 | May 31 | May 26 | May 20 |
| 32°F | Jun 3 | May 27 | May 22 | May 17 | May 13 | May 9 | May 4 | Apr 30 | Apr 26 |
| 28°F | May 9 | May 3 | Apr 29 | Apr 25 | Apr 21 | Apr 15 | Apr 10 | Apr 4 | Mar 28 |
| 24°F | Apr 13 | Apr 5 | Mar 31 | Mar 27 | Mar 22 | Mar 16 | Mar 12 | Mar 6 | Feb 28 |
| 20°F | Mar 15 | Mar 6 | Mar 1 | Feb 26 | Feb 21 | Feb 16 | Feb 10 | Feb 3 | Jan 21 |
| 16°F | Mar 3 | Feb 24 | Feb 18 | Feb 10 | Feb 5 | Jan 29 | Jan 18 | Jan 7 | Dec 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 | Aug 26 | Sep 2 | Sep 6 | Sep 10 | Sep 15 | Sep 19 | Sep 23 | Sep 28 | Oct 2 |
| 32°F | Sep 15 | Sep 24 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 19 |
| 28°F | Oct 3 | Oct 8 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 31 | Nov 6 |
| 24°F | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 9 | Nov 13 | Nov 20 | Nov 29 |
| 20°F | Oct 30 | Nov 6 | Nov 12 | Nov 18 | Nov 25 | Dec 1 | Dec 5 | Dec 14 | Dec 29 |
| 16°F | Nov 9 | Nov 18 | Nov 29 | Dec 5 | Dec 11 | Dec 19 | Dec 28 | Jan 5 | Jan 24 |
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 | 124 | 115 | 108 | 102 | 96 | 91 | 85 | 77 | 65 |
| 32°F | 167 | 159 | 153 | 148 | 142 | 138 | 132 | 125 | 116 |
| 28°F | 212 | 203 | 195 | 189 | 184 | 177 | 171 | 165 | 156 |
| 24°F | 263 | 251 | 243 | 236 | 229 | 223 | 216 | 208 | 197 |
| 20°F | 321 | 304 | 294 | 284 | 276 | 269 | 261 | 252 | 241 |
| 16°F | 360 | 344 | 334 | 323 | 314 | 307 | 300 | 289 | 270 |
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
- 92% 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
- 6,378
- Cooling degree days, base 65°F
- 132
- Growing degree days, base 40°F
- 3,617
- Growing degree days, base 45°F
- 2,483
- Growing degree days, base 50°F
- 1,579
- Growing degree days, base 55°F
- 885
- Growing degree days, base 60°F
- 404
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 977 | 0 | 0 |
| February | 805 | 0 | 0 |
| March | 738 | 0 | 4 |
| April | 570 | 0 | 25 |
| May | 377 | 2 | 128 |
| June | 221 | 11 | 244 |
| July | 82 | 60 | 443 |
| August | 89 | 50 | 426 |
| September | 213 | 9 | 252 |
| October | 521 | 0 | 53 |
| November | 789 | 0 | 3 |
| December | 998 | 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 5.1 km from Hood River 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 USC00356466 (Parkdale 1 Nne). Public domain.