Stratford Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Byars 3ESE Mesonet. 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 25 and the first fall freeze around November 8, a growing season of about 228 days.
- Median at 36°F
- last April 7, first October 31
- Median at 32°F
- last March 25, first November 8
- Median at 28°F
- last March 10, first November 18
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 25 | Apr 20 | Apr 15 | Apr 10 | Apr 7 | Apr 4 | Mar 31 | Mar 27 | Mar 20 |
| 32°F | Apr 13 | Apr 6 | Apr 2 | Mar 29 | Mar 25 | Mar 21 | Mar 16 | Mar 11 | Mar 3 |
| 28°F | Mar 31 | Mar 23 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 2 | Feb 26 | Feb 20 |
| 24°F | Mar 17 | Mar 11 | Mar 6 | Mar 2 | Feb 27 | Feb 23 | Feb 18 | Feb 12 | Feb 3 |
| 20°F | Mar 7 | Mar 1 | Feb 24 | Feb 19 | Feb 14 | Feb 9 | Feb 2 | Jan 29 | Jan 20 |
| 16°F | Feb 26 | Feb 17 | Feb 11 | Feb 5 | Feb 1 | Jan 28 | Jan 22 | Jan 15 | Jan 2 |
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 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 14 |
| 32°F | Oct 23 | Oct 29 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 24 |
| 28°F | Nov 1 | Nov 6 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 5 |
| 24°F | Nov 10 | Nov 16 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 13 | Dec 20 |
| 20°F | Nov 22 | Nov 30 | Dec 4 | Dec 11 | Dec 16 | Dec 21 | Dec 27 | Jan 2 | Jan 11 |
| 16°F | Dec 3 | Dec 12 | Dec 19 | Dec 25 | Dec 31 | Jan 4 | Jan 11 | Jan 18 | Jan 31 |
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 | 230 | 222 | 215 | 211 | 205 | 201 | 196 | 190 | 183 |
| 32°F | 254 | 245 | 240 | 234 | 228 | 223 | 217 | 212 | 202 |
| 28°F | 276 | 268 | 263 | 258 | 253 | 247 | 241 | 235 | 225 |
| 24°F | 304 | 295 | 288 | 281 | 277 | 272 | 265 | 258 | 248 |
| 20°F | 333 | 325 | 316 | 310 | 303 | 297 | 290 | 282 | 272 |
| 16°F | 364 | 351 | 341 | 335 | 330 | 323 | 315 | 307 | 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
- 99% of years
- 16°F or colder
- 90% 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
- 3,189
- Cooling degree days, base 65°F
- 2,027
- Growing degree days, base 40°F
- 8,281
- Growing degree days, base 45°F
- 6,736
- Growing degree days, base 50°F
- 5,327
- Growing degree days, base 55°F
- 4,071
- Growing degree days, base 60°F
- 2,970
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 753 | 0 | 28 |
| February | 578 | 3 | 65 |
| March | 393 | 15 | 177 |
| April | 161 | 50 | 354 |
| May | 43 | 175 | 598 |
| June | 0 | 377 | 826 |
| July | 0 | 519 | 984 |
| August | 0 | 520 | 985 |
| September | 16 | 272 | 707 |
| October | 146 | 87 | 417 |
| November | 399 | 8 | 151 |
| December | 699 | 1 | 37 |
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 7.1 km from Stratford. 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 USC00341283 (Byars 3ESE Mesonet). Public domain.