Brookside Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Newark Ag Farm. 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 7 and the first fall freeze around November 2, a growing season of about 208 days.
- Median at 36°F
- last April 22, first October 22
- Median at 32°F
- last April 7, first November 2
- Median at 28°F
- last March 27, first November 13
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 9 | May 2 | Apr 29 | Apr 25 | Apr 22 | Apr 20 | Apr 17 | Apr 13 | Apr 8 |
| 32°F | Apr 21 | Apr 18 | Apr 14 | Apr 10 | Apr 7 | Apr 5 | Apr 3 | Mar 31 | Mar 26 |
| 28°F | Apr 8 | Apr 4 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 17 | Mar 11 |
| 24°F | Mar 29 | Mar 24 | Mar 20 | Mar 17 | Mar 14 | Mar 11 | Mar 8 | Mar 4 | Feb 27 |
| 20°F | Mar 21 | Mar 15 | Mar 11 | Mar 7 | Mar 4 | Mar 1 | Feb 27 | Feb 22 | Feb 15 |
| 16°F | Mar 12 | Mar 5 | Mar 2 | Feb 26 | Feb 22 | Feb 16 | Feb 11 | Feb 6 | Jan 31 |
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 9 | Oct 13 | Oct 16 | Oct 20 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 4 |
| 32°F | Oct 19 | Oct 24 | Oct 28 | Nov 1 | Nov 2 | Nov 5 | Nov 7 | Nov 11 | Nov 17 |
| 28°F | Nov 1 | Nov 4 | Nov 8 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 24 | Dec 1 |
| 24°F | Nov 10 | Nov 16 | Nov 19 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 18 |
| 20°F | Nov 22 | Nov 30 | Dec 4 | Dec 9 | Dec 15 | Dec 20 | Dec 25 | Dec 31 | Jan 7 |
| 16°F | Dec 8 | Dec 17 | Dec 22 | Dec 27 | Jan 1 | Jan 4 | Jan 10 | Jan 16 | Jan 23 |
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 | 202 | 195 | 191 | 187 | 183 | 178 | 174 | 168 | 161 |
| 32°F | 228 | 221 | 216 | 212 | 208 | 205 | 201 | 196 | 190 |
| 28°F | 255 | 247 | 241 | 236 | 231 | 228 | 225 | 220 | 213 |
| 24°F | 283 | 275 | 268 | 263 | 258 | 253 | 248 | 242 | 235 |
| 20°F | 310 | 302 | 297 | 290 | 285 | 281 | 276 | 268 | 258 |
| 16°F | 333 | 324 | 318 | 313 | 308 | 304 | 298 | 293 | 284 |
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
- 4,591
- Cooling degree days, base 65°F
- 1,234
- Growing degree days, base 40°F
- 6,385
- Growing degree days, base 45°F
- 5,048
- Growing degree days, base 50°F
- 3,866
- Growing degree days, base 55°F
- 2,841
- Growing degree days, base 60°F
- 1,963
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 967 | 0 | 4 |
| February | 826 | 0 | 3 |
| March | 667 | 1 | 32 |
| April | 329 | 14 | 178 |
| May | 119 | 80 | 428 |
| June | 11 | 240 | 679 |
| July | 0 | 387 | 852 |
| August | 1 | 334 | 798 |
| September | 37 | 154 | 567 |
| October | 251 | 23 | 254 |
| November | 559 | 1 | 61 |
| December | 825 | 0 | 10 |
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 1.6 km from Brookside. 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 USC00076410 (Newark Ag Farm). Public domain.