Lawton Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Lawton. 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 26 and the first fall freeze around November 7, a growing season of about 225 days.
- Median at 36°F
- last April 7, first October 29
- Median at 32°F
- last March 26, first November 7
- Median at 28°F
- last March 11, first November 16
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 24 | Apr 19 | Apr 14 | Apr 10 | Apr 7 | Apr 4 | Apr 1 | Mar 28 | Mar 20 |
| 32°F | Apr 14 | Apr 7 | Apr 3 | Mar 31 | Mar 26 | Mar 21 | Mar 17 | Mar 12 | Mar 4 |
| 28°F | Apr 3 | Mar 26 | Mar 19 | Mar 15 | Mar 11 | Mar 7 | Mar 3 | Feb 28 | Feb 22 |
| 24°F | Mar 19 | Mar 11 | Mar 7 | Mar 3 | Feb 28 | Feb 26 | Feb 22 | Feb 17 | Feb 8 |
| 20°F | Mar 7 | Mar 1 | Feb 26 | Feb 21 | Feb 16 | Feb 11 | Feb 6 | Jan 31 | Jan 22 |
| 16°F | Feb 28 | Feb 21 | Feb 14 | Feb 8 | Feb 3 | Jan 29 | Jan 22 | Jan 13 | Dec 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 16 | Oct 20 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 5 | Nov 8 | Nov 13 |
| 32°F | Oct 21 | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 22 |
| 28°F | Oct 30 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 24 | Nov 30 | Dec 5 |
| 24°F | Nov 9 | Nov 16 | Nov 22 | Nov 27 | Nov 30 | Dec 3 | Dec 7 | Dec 12 | Dec 18 |
| 20°F | Nov 24 | Nov 30 | Dec 4 | Dec 9 | Dec 13 | Dec 18 | Dec 22 | Dec 28 | Jan 5 |
| 16°F | Dec 5 | Dec 11 | Dec 18 | Dec 22 | Dec 28 | Jan 2 | Jan 9 | Jan 19 | Feb 1 |
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 | 228 | 219 | 214 | 209 | 204 | 200 | 195 | 189 | 182 |
| 32°F | 253 | 244 | 237 | 231 | 225 | 220 | 215 | 209 | 200 |
| 28°F | 277 | 269 | 263 | 257 | 252 | 245 | 240 | 232 | 221 |
| 24°F | 304 | 292 | 285 | 280 | 275 | 270 | 265 | 258 | 248 |
| 20°F | 333 | 321 | 312 | 307 | 300 | 295 | 289 | 281 | 272 |
| 16°F | 364 | 352 | 342 | 334 | 327 | 320 | 313 | 305 | 296 |
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
- 91% 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
- 3,280
- Cooling degree days, base 65°F
- 2,236
- Growing degree days, base 40°F
- 8,380
- Growing degree days, base 45°F
- 6,851
- Growing degree days, base 50°F
- 5,471
- Growing degree days, base 55°F
- 4,245
- Growing degree days, base 60°F
- 3,172
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 786 | 0 | 14 |
| February | 600 | 1 | 38 |
| March | 390 | 10 | 171 |
| April | 172 | 40 | 332 |
| May | 32 | 198 | 631 |
| June | 1 | 422 | 871 |
| July | 0 | 590 | 1,055 |
| August | 0 | 581 | 1,046 |
| September | 15 | 305 | 740 |
| October | 133 | 80 | 422 |
| November | 431 | 9 | 130 |
| December | 721 | 0 | 21 |
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 6.2 km from Lawton. 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 USC00345063 (Lawton). Public domain.