Marshall Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Marshall. 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 11 and the first fall freeze around October 26, a growing season of about 197 days.
- Median at 36°F
- last April 24, first October 16
- Median at 32°F
- last April 11, first October 26
- Median at 28°F
- last March 30, first November 6
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 8 | May 3 | Apr 30 | Apr 27 | Apr 24 | Apr 21 | Apr 17 | Apr 14 | Apr 8 |
| 32°F | Apr 27 | Apr 22 | Apr 18 | Apr 15 | Apr 11 | Apr 8 | Apr 4 | Mar 31 | Mar 25 |
| 28°F | Apr 16 | Apr 10 | Apr 5 | Apr 2 | Mar 30 | Mar 26 | Mar 21 | Mar 16 | Mar 9 |
| 24°F | Apr 4 | Mar 29 | Mar 24 | Mar 19 | Mar 16 | Mar 12 | Mar 8 | Mar 3 | Feb 25 |
| 20°F | Mar 25 | Mar 18 | Mar 15 | Mar 11 | Mar 7 | Mar 2 | Feb 27 | Feb 21 | Feb 10 |
| 16°F | Mar 15 | Mar 9 | Mar 3 | Feb 28 | Feb 24 | Feb 16 | Feb 10 | Feb 2 | Jan 26 |
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 1 | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 30 |
| 32°F | Oct 10 | Oct 17 | Oct 20 | Oct 24 | Oct 26 | Oct 30 | Nov 1 | Nov 5 | Nov 11 |
| 28°F | Oct 21 | Oct 27 | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 14 | Nov 19 | Nov 27 |
| 24°F | Oct 31 | Nov 5 | Nov 11 | Nov 16 | Nov 20 | Nov 23 | Nov 28 | Dec 2 | Dec 8 |
| 20°F | Nov 9 | Nov 19 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 11 | Dec 17 | Dec 23 |
| 16°F | Nov 24 | Dec 1 | Dec 7 | Dec 12 | Dec 18 | Dec 22 | Dec 27 | Jan 1 | Jan 11 |
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 | 196 | 188 | 183 | 179 | 175 | 170 | 165 | 160 | 153 |
| 32°F | 222 | 214 | 207 | 203 | 197 | 193 | 187 | 182 | 175 |
| 28°F | 248 | 239 | 233 | 227 | 222 | 217 | 212 | 207 | 197 |
| 24°F | 273 | 264 | 258 | 252 | 248 | 243 | 236 | 230 | 220 |
| 20°F | 300 | 290 | 283 | 276 | 270 | 264 | 258 | 251 | 242 |
| 16°F | 330 | 318 | 309 | 303 | 297 | 290 | 284 | 276 | 267 |
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
- 3,952
- Cooling degree days, base 65°F
- 1,460
- Growing degree days, base 40°F
- 7,146
- Growing degree days, base 45°F
- 5,705
- Growing degree days, base 50°F
- 4,412
- Growing degree days, base 55°F
- 3,272
- Growing degree days, base 60°F
- 2,290
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 882 | 0 | 18 |
| February | 685 | 1 | 32 |
| March | 514 | 6 | 107 |
| April | 248 | 28 | 262 |
| May | 80 | 110 | 496 |
| June | 5 | 278 | 723 |
| July | 0 | 415 | 880 |
| August | 1 | 389 | 852 |
| September | 38 | 186 | 599 |
| October | 220 | 44 | 313 |
| November | 494 | 5 | 102 |
| December | 785 | 0 | 28 |
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 2.3 km from Marshall. 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 USC00034666 (Marshall). Public domain.