Palatine Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Barrington 3SW. 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 25 and the first fall freeze around October 19, a growing season of about 177 days.
- Median at 36°F
- last May 6, first October 11
- Median at 32°F
- last April 25, first October 19
- Median at 28°F
- last April 12, first October 30
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 25 | May 19 | May 15 | May 9 | May 6 | May 3 | Apr 30 | Apr 27 | Apr 22 |
| 32°F | May 12 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 21 | Apr 18 | Apr 15 | Apr 10 |
| 28°F | Apr 30 | Apr 23 | Apr 18 | Apr 16 | Apr 12 | Apr 9 | Apr 7 | Apr 4 | Mar 31 |
| 24°F | Apr 16 | Apr 10 | Apr 6 | Apr 4 | Apr 2 | Mar 31 | Mar 27 | Mar 23 | Mar 18 |
| 20°F | Apr 4 | Mar 31 | Mar 29 | Mar 25 | Mar 23 | Mar 19 | Mar 16 | Mar 12 | Mar 7 |
| 16°F | Mar 28 | Mar 24 | Mar 20 | Mar 17 | Mar 14 | Mar 11 | Mar 8 | Mar 4 | Feb 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 | Sep 27 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 13 | Oct 15 | Oct 18 | Oct 23 |
| 32°F | Oct 5 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Nov 1 |
| 28°F | Oct 15 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 7 | Nov 12 |
| 24°F | Oct 27 | Nov 1 | Nov 2 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 24 |
| 20°F | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 26 | Nov 30 | Dec 4 |
| 16°F | Nov 12 | Nov 18 | Nov 22 | Nov 25 | Nov 29 | 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 | 176 | 169 | 163 | 158 | 154 | 150 | 145 | 140 | 132 |
| 32°F | 196 | 190 | 184 | 181 | 177 | 172 | 167 | 162 | 152 |
| 28°F | 218 | 212 | 208 | 204 | 200 | 196 | 191 | 185 | 178 |
| 24°F | 241 | 234 | 229 | 226 | 221 | 217 | 214 | 209 | 202 |
| 20°F | 264 | 256 | 251 | 246 | 242 | 237 | 233 | 227 | 221 |
| 16°F | 282 | 273 | 268 | 263 | 259 | 255 | 251 | 246 | 238 |
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
- 6,816
- Cooling degree days, base 65°F
- 652
- Growing degree days, base 40°F
- 4,825
- Growing degree days, base 45°F
- 3,731
- Growing degree days, base 50°F
- 2,764
- Growing degree days, base 55°F
- 1,924
- Growing degree days, base 60°F
- 1,214
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,362 | 0 | 0 |
| February | 1,131 | 0 | 1 |
| March | 916 | 1 | 17 |
| April | 533 | 4 | 84 |
| May | 244 | 39 | 284 |
| June | 53 | 137 | 535 |
| July | 9 | 224 | 680 |
| August | 14 | 175 | 626 |
| September | 127 | 67 | 395 |
| October | 446 | 6 | 123 |
| November | 803 | 0 | 18 |
| December | 1,180 | 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 10.7 km from Palatine. 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 USC00110442 (Barrington 3SW). Public domain.