Reedsport Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Winchester Bay Coast Grd. 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 March 25 and the first fall freeze around November 24, a growing season of about 249 days.
- Median at 36°F
- last April 27, first October 30
- Median at 32°F
- last March 25, first November 24
- Median at 28°F
- last February 17, first December 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 | May 19 | May 10 | May 4 | Apr 30 | Apr 27 | Apr 22 | Apr 16 | Apr 8 | Mar 31 |
| 32°F | Apr 27 | Apr 14 | Apr 4 | Mar 30 | Mar 25 | Mar 15 | Mar 5 | Feb 24 | Feb 15 |
| 28°F | Mar 29 | Mar 14 | Mar 5 | Feb 26 | Feb 17 | Feb 9 | Jan 28 | Jan 9 | Dec 23 |
| 24°F | Mar 4 | Feb 23 | Feb 16 | Feb 4 | Jan 24 | Jan 10 | Jan 2 | Dec 23 | Dec 12 |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | Oct 8 | Oct 17 | Oct 21 | Oct 25 | Oct 30 | Nov 3 | Nov 8 | Nov 15 | Nov 25 |
| 32°F | Oct 27 | Nov 4 | Nov 10 | Nov 17 | Nov 24 | Dec 1 | Dec 7 | Dec 16 | Jan 1 |
| 28°F | Nov 15 | Nov 28 | Dec 8 | Dec 16 | Dec 26 | Jan 3 | Jan 15 | Feb 2 | Feb 19 |
| 24°F | Dec 7 | Dec 15 | Dec 24 | Jan 2 | Jan 10 | Jan 23 | Feb 4 | Feb 14 | Mar 2 |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | 222 | 211 | 203 | 195 | 188 | 181 | 174 | 167 | 157 |
| 32°F | 304 | 278 | 268 | 259 | 249 | 239 | 229 | 216 | 202 |
| 28°F | 365 | 356 | 337 | 324 | 314 | 305 | 295 | 282 | 265 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 358 | 338 | 314 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
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
- 85% of years
- 24°F or colder
- 37% of years
- 20°F or colder
- 10% of years
- 16°F or colder
- 2% 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
- 4,355
- Cooling degree days, base 65°F
- 24
- Growing degree days, base 40°F
- 4,816
- Growing degree days, base 45°F
- 3,120
- Growing degree days, base 50°F
- 1,733
- Growing degree days, base 55°F
- 762
- Growing degree days, base 60°F
- 199
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 570 | 0 | 19 |
| February | 503 | 0 | 23 |
| March | 529 | 0 | 31 |
| April | 438 | 0 | 60 |
| May | 334 | 1 | 142 |
| June | 226 | 1 | 226 |
| July | 137 | 4 | 332 |
| August | 124 | 5 | 346 |
| September | 148 | 10 | 312 |
| October | 305 | 2 | 172 |
| November | 455 | 0 | 53 |
| December | 586 | 0 | 18 |
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 6.9 km from Reedsport. 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 USC00353193 (Winchester Bay Coast Grd). Public domain.