Bloomfield Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Bloomfield. 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 16 and the first fall freeze around October 22, a growing season of about 188 days.
- Median at 36°F
- last April 28, first October 11
- Median at 32°F
- last April 16, first October 22
- Median at 28°F
- last April 6, 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 10 | May 5 | May 2 | Apr 30 | Apr 28 | Apr 25 | Apr 22 | Apr 17 | Apr 13 |
| 32°F | Apr 30 | Apr 26 | Apr 23 | Apr 19 | Apr 16 | Apr 13 | Apr 10 | Apr 6 | Apr 1 |
| 28°F | Apr 20 | Apr 16 | Apr 11 | Apr 9 | Apr 6 | Apr 4 | Apr 1 | Mar 29 | Mar 22 |
| 24°F | Apr 11 | Apr 6 | Apr 3 | Mar 31 | Mar 29 | Mar 25 | Mar 21 | Mar 16 | Mar 11 |
| 20°F | Apr 2 | Mar 30 | Mar 25 | Mar 21 | Mar 17 | Mar 14 | Mar 11 | Mar 7 | Mar 3 |
| 16°F | Mar 27 | Mar 20 | Mar 16 | Mar 12 | Mar 10 | Mar 7 | Mar 4 | Mar 1 | Feb 22 |
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 26 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 24 |
| 32°F | Oct 5 | Oct 12 | Oct 16 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 30 | Nov 2 |
| 28°F | Oct 19 | Oct 24 | Oct 27 | Oct 29 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 12 |
| 24°F | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 25 |
| 20°F | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 26 | Dec 1 | Dec 5 |
| 16°F | Nov 11 | Nov 17 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 8 | Dec 15 |
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 | 186 | 179 | 175 | 171 | 167 | 162 | 158 | 153 | 147 |
| 32°F | 207 | 200 | 195 | 191 | 188 | 183 | 180 | 173 | 166 |
| 28°F | 227 | 220 | 215 | 211 | 208 | 205 | 200 | 195 | 190 |
| 24°F | 248 | 240 | 234 | 229 | 226 | 222 | 217 | 213 | 206 |
| 20°F | 268 | 259 | 254 | 248 | 244 | 239 | 234 | 228 | 221 |
| 16°F | 285 | 277 | 270 | 265 | 261 | 257 | 253 | 246 | 239 |
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
- 6,035
- Cooling degree days, base 65°F
- 1,044
- Growing degree days, base 40°F
- 5,700
- Growing degree days, base 45°F
- 4,516
- Growing degree days, base 50°F
- 3,456
- Growing degree days, base 55°F
- 2,520
- Growing degree days, base 60°F
- 1,714
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,291 | 0 | 0 |
| February | 1,046 | 0 | 3 |
| March | 792 | 1 | 38 |
| April | 421 | 7 | 135 |
| May | 154 | 64 | 382 |
| June | 16 | 217 | 651 |
| July | 1 | 339 | 803 |
| August | 5 | 284 | 744 |
| September | 86 | 115 | 482 |
| October | 363 | 16 | 186 |
| November | 740 | 0 | 30 |
| December | 1,121 | 0 | 2 |
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 1.4 km from Bloomfield. 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 USC00130753 (Bloomfield). Public domain.