Redfield Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Redfield. 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 8 and the first fall freeze around October 1, a growing season of about 145 days.
- Median at 36°F
- last May 16, first September 23
- Median at 32°F
- last May 8, first October 1
- Median at 28°F
- last April 29, first October 8
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 29 | May 25 | May 21 | May 18 | May 16 | May 14 | May 11 | May 8 | May 5 |
| 32°F | May 21 | May 16 | May 13 | May 10 | May 8 | May 5 | May 2 | Apr 30 | Apr 25 |
| 28°F | May 12 | May 7 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 19 | Apr 14 |
| 24°F | May 4 | Apr 30 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 9 | Apr 5 |
| 20°F | Apr 26 | Apr 20 | Apr 16 | Apr 13 | Apr 10 | Apr 8 | Apr 5 | Apr 2 | Mar 27 |
| 16°F | Apr 16 | Apr 11 | Apr 7 | Apr 5 | Apr 3 | Mar 31 | Mar 28 | Mar 22 | Mar 15 |
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 | Sep 10 | Sep 16 | Sep 19 | Sep 21 | Sep 23 | Sep 25 | Sep 28 | Oct 1 | Oct 4 |
| 32°F | Sep 19 | Sep 22 | Sep 26 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 13 |
| 28°F | Sep 25 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 18 | Oct 22 |
| 24°F | Oct 2 | Oct 7 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 30 |
| 20°F | Oct 13 | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 10 |
| 16°F | Oct 22 | Oct 28 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 19 |
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 | 146 | 140 | 136 | 133 | 129 | 126 | 123 | 118 | 112 |
| 32°F | 162 | 157 | 153 | 149 | 145 | 142 | 138 | 134 | 128 |
| 28°F | 180 | 174 | 169 | 165 | 162 | 158 | 154 | 150 | 142 |
| 24°F | 198 | 191 | 186 | 182 | 179 | 175 | 171 | 166 | 158 |
| 20°F | 219 | 212 | 207 | 203 | 198 | 194 | 190 | 185 | 178 |
| 16°F | 238 | 231 | 225 | 220 | 215 | 211 | 207 | 201 | 194 |
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
- 8,245
- Cooling degree days, base 65°F
- 617
- Growing degree days, base 40°F
- 4,400
- Growing degree days, base 45°F
- 3,410
- Growing degree days, base 50°F
- 2,534
- Growing degree days, base 55°F
- 1,771
- Growing degree days, base 60°F
- 1,130
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,616 | 0 | 0 |
| February | 1,335 | 0 | 0 |
| March | 1,067 | 0 | 4 |
| April | 634 | 1 | 48 |
| May | 287 | 24 | 243 |
| June | 56 | 119 | 513 |
| July | 12 | 235 | 688 |
| August | 28 | 178 | 615 |
| September | 178 | 60 | 345 |
| October | 584 | 2 | 74 |
| November | 1,010 | 0 | 4 |
| December | 1,438 | 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 1.3 km from Redfield. 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 USC00397052 (Redfield). Public domain.