Pulaski County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Grand Chain Dam 53. 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 3 and the first fall freeze around November 5, a growing season of about 216 days.
- Median at 36°F
- last April 14, first October 25
- Median at 32°F
- last April 3, first November 5
- Median at 28°F
- last March 22, first November 17
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 2 | Apr 27 | Apr 22 | Apr 18 | Apr 14 | Apr 11 | Apr 8 | Apr 5 | Mar 31 |
| 32°F | Apr 21 | Apr 14 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 27 | Mar 23 | Mar 17 |
| 28°F | Apr 7 | Apr 2 | Mar 30 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 10 | Mar 2 |
| 24°F | Mar 30 | Mar 23 | Mar 19 | Mar 15 | Mar 11 | Mar 7 | Mar 2 | Feb 26 | Feb 17 |
| 20°F | Mar 20 | Mar 14 | Mar 8 | Mar 3 | Feb 28 | Feb 23 | Feb 16 | Feb 9 | Feb 2 |
| 16°F | Mar 12 | Mar 4 | Feb 27 | Feb 21 | Feb 15 | Feb 9 | Feb 4 | Jan 30 | Jan 20 |
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 13 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 27 | Oct 30 | Nov 1 | Nov 6 |
| 32°F | Oct 23 | Oct 27 | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 12 | Nov 15 | Nov 22 |
| 28°F | Nov 3 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 4 |
| 24°F | Nov 10 | Nov 15 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 6 | Dec 11 | Dec 18 |
| 20°F | Nov 19 | Nov 26 | Dec 1 | Dec 5 | Dec 10 | Dec 13 | Dec 19 | Dec 24 | Dec 31 |
| 16°F | Nov 30 | Dec 7 | Dec 12 | Dec 18 | Dec 24 | Dec 29 | Jan 1 | Jan 7 | Jan 16 |
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 | 211 | 205 | 200 | 197 | 193 | 188 | 184 | 179 | 172 |
| 32°F | 238 | 230 | 225 | 221 | 216 | 211 | 206 | 202 | 194 |
| 28°F | 263 | 255 | 249 | 244 | 239 | 235 | 229 | 223 | 214 |
| 24°F | 289 | 280 | 273 | 268 | 261 | 256 | 250 | 243 | 235 |
| 20°F | 314 | 304 | 297 | 291 | 284 | 278 | 272 | 265 | 256 |
| 16°F | 338 | 327 | 320 | 313 | 307 | 301 | 295 | 286 | 275 |
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
- 4,102
- Cooling degree days, base 65°F
- 1,546
- Growing degree days, base 40°F
- 7,149
- Growing degree days, base 45°F
- 5,731
- Growing degree days, base 50°F
- 4,461
- Growing degree days, base 55°F
- 3,339
- Growing degree days, base 60°F
- 2,368
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 941 | 0 | 10 |
| February | 738 | 0 | 17 |
| March | 558 | 2 | 80 |
| April | 248 | 23 | 254 |
| May | 71 | 121 | 515 |
| June | 5 | 310 | 754 |
| July | 0 | 430 | 894 |
| August | 0 | 400 | 865 |
| September | 22 | 215 | 643 |
| October | 204 | 43 | 318 |
| November | 506 | 3 | 90 |
| December | 809 | 0 | 20 |
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 Pulaski 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 USC00113580 (Grand Chain Dam 53). Public domain.