Waskom Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Shreveport WFO. 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 March 6 and the first fall freeze around November 19, a growing season of about 257 days.
- Median at 36°F
- last March 25, first November 8
- Median at 32°F
- last March 6, first November 19
- Median at 28°F
- last February 20, first December 3
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 | Apr 12 | Apr 6 | Apr 3 | Mar 31 | Mar 25 | Mar 20 | Mar 15 | Mar 9 | Mar 1 |
| 32°F | Mar 29 | Mar 20 | Mar 15 | Mar 10 | Mar 6 | Mar 2 | Feb 28 | Feb 22 | Feb 13 |
| 28°F | Mar 14 | Mar 6 | Mar 1 | Feb 26 | Feb 20 | Feb 13 | Feb 6 | Jan 31 | Jan 22 |
| 24°F | Mar 1 | Feb 20 | Feb 11 | Feb 5 | Jan 31 | Jan 26 | Jan 19 | Jan 13 | Jan 1 |
| 20°F | Feb 16 | Feb 6 | Jan 31 | Jan 23 | Jan 18 | Jan 14 | Jan 8 | Jan 2 | Dec 25 |
| 16°F | Feb 7 | Feb 1 | Jan 25 | Jan 20 | Jan 14 | Jan 9 | Jan 5 | Jan 2 | Dec 24 |
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 25 | Oct 30 | Nov 3 | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 19 | Nov 25 |
| 32°F | Nov 2 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 23 | Nov 28 | Dec 2 | Dec 8 |
| 28°F | Nov 11 | Nov 19 | Nov 25 | Nov 29 | Dec 3 | Dec 8 | Dec 13 | Dec 22 | Jan 1 |
| 24°F | Nov 26 | Dec 4 | Dec 11 | Dec 20 | Dec 26 | Jan 1 | Jan 5 | Jan 13 | Jan 24 |
| 20°F | Dec 12 | Dec 24 | Dec 29 | Jan 1 | Jan 6 | Jan 12 | Jan 17 | Jan 23 | Feb 2 |
| 16°F | Dec 18 | Dec 29 | Jan 2 | Jan 5 | Jan 9 | Jan 13 | Jan 20 | Jan 29 | Feb 5 |
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 | 255 | 246 | 240 | 234 | 229 | 224 | 220 | 214 | 205 |
| 32°F | 285 | 276 | 270 | 264 | 257 | 251 | 245 | 238 | 229 |
| 28°F | 325 | 311 | 303 | 296 | 289 | 282 | 275 | 268 | 258 |
| 24°F | 363 | 348 | 339 | 333 | 327 | 320 | 310 | 301 | 288 |
| 20°F | 365 | 365 | 365 | 365 | 359 | 350 | 342 | 333 | 322 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 347 |
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
- 92% of years
- 20°F or colder
- 60% of years
- 16°F or colder
- 23% 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
- 2,254
- Cooling degree days, base 65°F
- 2,405
- Growing degree days, base 40°F
- 9,366
- Growing degree days, base 45°F
- 7,695
- Growing degree days, base 50°F
- 6,145
- Growing degree days, base 55°F
- 4,733
- Growing degree days, base 60°F
- 3,482
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 568 | 3 | 77 |
| February | 419 | 7 | 120 |
| March | 248 | 27 | 273 |
| April | 95 | 75 | 435 |
| May | 11 | 256 | 710 |
| June | 0 | 427 | 877 |
| July | 0 | 547 | 1,012 |
| August | 0 | 559 | 1,024 |
| September | 2 | 357 | 805 |
| October | 80 | 122 | 508 |
| November | 300 | 20 | 214 |
| December | 531 | 5 | 90 |
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 20.7 km from Waskom. 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 USC00168448 (Shreveport WFO). Public domain.