Chenango County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Norwich. 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 4, a growing season of about 142 days.
- Median at 36°F
- last May 26, first September 25
- Median at 32°F
- last May 13, first October 4
- Median at 28°F
- last May 1, first October 15
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 | Jun 6 | Jun 2 | May 31 | May 28 | May 26 | May 23 | May 20 | May 16 | May 11 |
| 32°F | May 27 | May 23 | May 20 | May 17 | May 13 | May 10 | May 7 | May 3 | Apr 28 |
| 28°F | May 17 | May 12 | May 7 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 18 |
| 24°F | May 3 | Apr 28 | Apr 24 | Apr 21 | Apr 19 | Apr 16 | Apr 12 | Apr 8 | Apr 3 |
| 20°F | Apr 20 | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Apr 2 | Mar 31 | Mar 28 |
| 16°F | Apr 10 | Apr 6 | Apr 3 | Apr 2 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 18 |
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 12 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Sep 30 | Oct 3 | Oct 7 |
| 32°F | Sep 20 | Sep 25 | Sep 29 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 13 | Oct 18 |
| 28°F | Sep 29 | Oct 3 | Oct 7 | Oct 11 | Oct 15 | Oct 19 | Oct 22 | Oct 27 | Nov 1 |
| 24°F | Oct 11 | Oct 17 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
| 20°F | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 20 | Nov 25 |
| 16°F | Nov 6 | Nov 10 | Nov 14 | Nov 18 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 7 |
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 | 141 | 133 | 129 | 126 | 121 | 118 | 114 | 109 | 102 |
| 32°F | 162 | 155 | 150 | 146 | 142 | 139 | 134 | 130 | 123 |
| 28°F | 186 | 179 | 174 | 169 | 164 | 159 | 155 | 149 | 143 |
| 24°F | 213 | 206 | 200 | 195 | 191 | 186 | 181 | 175 | 165 |
| 20°F | 234 | 227 | 223 | 220 | 216 | 212 | 208 | 204 | 198 |
| 16°F | 254 | 248 | 243 | 238 | 235 | 230 | 227 | 224 | 217 |
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
- 7,295
- Cooling degree days, base 65°F
- 375
- Growing degree days, base 40°F
- 4,175
- Growing degree days, base 45°F
- 3,140
- Growing degree days, base 50°F
- 2,236
- Growing degree days, base 55°F
- 1,465
- Growing degree days, base 60°F
- 837
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,344 | 0 | 0 |
| February | 1,182 | 0 | 0 |
| March | 1,045 | 0 | 5 |
| April | 626 | 2 | 48 |
| May | 306 | 17 | 213 |
| June | 83 | 74 | 442 |
| July | 20 | 140 | 584 |
| August | 34 | 107 | 538 |
| September | 178 | 34 | 313 |
| October | 510 | 2 | 82 |
| November | 828 | 0 | 10 |
| December | 1,141 | 0 | 1 |
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 7.8 km from Chenango 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 USC00306085 (Norwich). Public domain.