Spry Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for York 3 Ssw Pump Stn. 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 April 26 and the first fall freeze around October 19, a growing season of about 177 days.
- Median at 36°F
- last May 8, first October 8
- Median at 32°F
- last April 26, first October 19
- Median at 28°F
- last April 8, first October 31
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 24 | May 19 | May 15 | May 11 | May 8 | May 4 | May 1 | Apr 29 | Apr 23 |
| 32°F | May 13 | May 7 | May 2 | Apr 30 | Apr 26 | Apr 23 | Apr 18 | Apr 14 | Apr 7 |
| 28°F | Apr 26 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 30 | Mar 24 |
| 24°F | Apr 10 | Apr 5 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 17 | Mar 11 |
| 20°F | Mar 30 | Mar 25 | Mar 22 | Mar 18 | Mar 15 | Mar 12 | Mar 8 | Mar 4 | Feb 27 |
| 16°F | Mar 20 | Mar 16 | Mar 12 | Mar 8 | Mar 5 | Mar 1 | Feb 27 | Feb 22 | Feb 14 |
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 25 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 10 | Oct 14 | Oct 17 | Oct 22 |
| 32°F | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 |
| 28°F | Oct 15 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 8 | Nov 13 |
| 24°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 | Nov 29 |
| 20°F | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 13 |
| 16°F | Nov 20 | Nov 29 | Dec 2 | Dec 5 | Dec 9 | Dec 14 | Dec 18 | Dec 23 | Dec 31 |
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 | 175 | 167 | 162 | 157 | 153 | 149 | 145 | 139 | 133 |
| 32°F | 200 | 192 | 186 | 181 | 177 | 172 | 167 | 162 | 155 |
| 28°F | 225 | 217 | 212 | 207 | 203 | 199 | 195 | 189 | 182 |
| 24°F | 249 | 242 | 236 | 231 | 227 | 223 | 219 | 214 | 207 |
| 20°F | 278 | 270 | 264 | 259 | 254 | 249 | 244 | 238 | 231 |
| 16°F | 305 | 296 | 291 | 285 | 279 | 274 | 268 | 263 | 252 |
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
- 5,017
- Cooling degree days, base 65°F
- 1,025
- Growing degree days, base 40°F
- 5,971
- Growing degree days, base 45°F
- 4,689
- Growing degree days, base 50°F
- 3,556
- Growing degree days, base 55°F
- 2,570
- Growing degree days, base 60°F
- 1,727
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,046 | 0 | 4 |
| February | 861 | 0 | 5 |
| March | 703 | 1 | 35 |
| April | 356 | 14 | 168 |
| May | 130 | 71 | 409 |
| June | 19 | 205 | 636 |
| July | 0 | 322 | 787 |
| August | 2 | 274 | 736 |
| September | 58 | 121 | 514 |
| October | 309 | 18 | 207 |
| November | 618 | 0 | 47 |
| December | 914 | 0 | 9 |
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 5.5 km from Spry. 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 USC00369933 (York 3 Ssw Pump Stn). Public domain.