Coram Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Mt Sinai. 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 4 and the first fall freeze around November 7, a growing season of about 215 days.
- Median at 36°F
- last April 20, first October 26
- Median at 32°F
- last April 4, first November 7
- Median at 28°F
- last March 27, first November 22
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 7 | May 2 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 14 | Apr 10 | Apr 6 |
| 32°F | Apr 19 | Apr 13 | Apr 10 | Apr 7 | Apr 4 | Apr 3 | Apr 1 | Mar 29 | Mar 23 |
| 28°F | Apr 7 | Apr 3 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 20 | Mar 16 | Mar 11 |
| 24°F | Mar 31 | Mar 26 | Mar 23 | Mar 20 | Mar 16 | Mar 14 | Mar 11 | Mar 7 | Mar 1 |
| 20°F | Mar 22 | Mar 18 | Mar 14 | Mar 11 | Mar 8 | Mar 5 | Mar 1 | Feb 25 | Feb 15 |
| 16°F | Mar 15 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 20 | Feb 13 | Feb 6 | Jan 28 |
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 10 | Oct 15 | Oct 18 | Oct 22 | Oct 26 | Oct 30 | Nov 2 | Nov 6 | Nov 10 |
| 32°F | Oct 20 | Oct 26 | Oct 30 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 18 | Nov 24 |
| 28°F | Nov 2 | Nov 9 | Nov 14 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 9 |
| 24°F | Nov 18 | Nov 25 | Nov 30 | Dec 2 | Dec 6 | Dec 9 | Dec 13 | Dec 18 | Dec 24 |
| 20°F | Dec 1 | Dec 6 | Dec 10 | Dec 15 | Dec 19 | Dec 23 | Dec 27 | Jan 1 | Jan 8 |
| 16°F | Dec 10 | Dec 19 | Dec 25 | Dec 29 | Jan 1 | Jan 5 | Jan 10 | Jan 14 | Jan 22 |
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 | 210 | 203 | 198 | 192 | 187 | 183 | 178 | 173 | 165 |
| 32°F | 236 | 228 | 223 | 219 | 215 | 210 | 205 | 201 | 195 |
| 28°F | 262 | 255 | 249 | 245 | 241 | 236 | 231 | 225 | 217 |
| 24°F | 288 | 279 | 274 | 268 | 264 | 259 | 255 | 248 | 240 |
| 20°F | 312 | 303 | 297 | 292 | 286 | 281 | 276 | 270 | 261 |
| 16°F | 333 | 324 | 317 | 311 | 306 | 302 | 297 | 290 | 281 |
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
- 99% 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
- 4,698
- Cooling degree days, base 65°F
- 982
- Growing degree days, base 40°F
- 6,086
- Growing degree days, base 45°F
- 4,735
- Growing degree days, base 50°F
- 3,534
- Growing degree days, base 55°F
- 2,519
- Growing degree days, base 60°F
- 1,672
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 972 | 0 | 5 |
| February | 830 | 0 | 7 |
| March | 731 | 0 | 24 |
| April | 360 | 7 | 145 |
| May | 143 | 36 | 359 |
| June | 24 | 164 | 589 |
| July | 0 | 319 | 784 |
| August | 1 | 292 | 756 |
| September | 50 | 139 | 540 |
| October | 278 | 24 | 237 |
| November | 507 | 1 | 73 |
| December | 803 | 0 | 17 |
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 7.3 km from Coram. 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 USC00305606 (Mt Sinai). Public domain.