La Marque Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Galveston Scholes Fld. A median date has an even chance of a later freeze in spring, or an earlier one in fall.
A freeze (32°F or colder) happens in only 48 percent of years at Galveston Scholes Fld, so there is no typical freeze season.
- Median at 36°F
- last January 30, first December 26
- Median at 32°F
- last January 18, first January 7
- Median at 28°F
- last January 9, first January 8
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 | Mar 2 | Feb 20 | Feb 11 | Feb 4 | Jan 30 | Jan 24 | Jan 17 | Jan 10 | Dec 30 |
| 32°F | Feb 18 | Feb 7 | Jan 31 | Jan 26 | Jan 18 | Jan 12 | Jan 7 | Jan 1 | Dec 21 |
| 28°F | Feb 11 | Feb 1 | Jan 26 | Jan 19 | Jan 9 | Jan 7 | Jan 1 | Dec 23 | Dec 17 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | Dec 1 | Dec 7 | Dec 15 | Dec 21 | Dec 26 | Jan 1 | Jan 6 | Jan 12 | Jan 23 |
| 32°F | Dec 13 | Dec 21 | Dec 29 | Jan 3 | Jan 7 | Jan 13 | Jan 19 | Jan 29 | Feb 7 |
| 28°F | Dec 15 | Dec 21 | Dec 28 | Jan 2 | Jan 8 | Jan 12 | Jan 21 | Feb 1 | Feb 8 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | 365 | 356 | 346 | 340 | 334 | 327 | 319 | 310 | 298 |
| 32°F | 365 | 365 | 365 | 365 | 365 | 358 | 349 | 340 | 328 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 358 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
How often it gets that cold
The share of years with at least one night at or below each temperature.
- 36°F or colder
- 88% of years
- 32°F or colder
- 48% of years
- 28°F or colder
- 13% of years
- 24°F or colder
- 1% of years
- 20°F or colder
- 0% of years
- 16°F or colder
- 0% 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
- 889
- Cooling degree days, base 65°F
- 3,571
- Growing degree days, base 40°F
- 11,812
- Growing degree days, base 45°F
- 10,005
- Growing degree days, base 50°F
- 8,235
- Growing degree days, base 55°F
- 6,544
- Growing degree days, base 60°F
- 4,978
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 290 | 13 | 225 |
| February | 182 | 24 | 277 |
| March | 78 | 84 | 474 |
| April | 12 | 207 | 645 |
| May | 0 | 409 | 874 |
| June | 0 | 564 | 1,014 |
| July | 0 | 636 | 1,101 |
| August | 0 | 648 | 1,113 |
| September | 0 | 522 | 972 |
| October | 8 | 328 | 786 |
| November | 89 | 105 | 470 |
| December | 230 | 31 | 285 |
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 15.2 km from La Marque. 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 USW00012923 (Galveston Scholes Fld). Public domain.