Lompoc Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Lompoc. 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 January 20 and the first fall freeze around December 19, a growing season of about 335 days.
- Median at 36°F
- last February 28, first December 1
- Median at 32°F
- last January 20, first December 19
- Median at 28°F
- last January 1, first December 29
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 5 | Mar 27 | Mar 16 | Mar 7 | Feb 28 | Feb 23 | Feb 16 | Feb 7 | Jan 26 |
| 32°F | Feb 24 | Feb 12 | Feb 3 | Jan 27 | Jan 20 | Jan 11 | Jan 3 | Dec 27 | Dec 16 |
| 28°F | Jan 30 | Jan 18 | Jan 10 | Jan 5 | Jan 1 | Dec 29 | Dec 25 | Dec 20 | Dec 13 |
| 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 | Nov 3 | Nov 16 | Nov 21 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 22 |
| 32°F | Nov 27 | Dec 6 | Dec 10 | Dec 14 | Dec 19 | Dec 26 | Jan 1 | Jan 7 | Jan 26 |
| 28°F | Dec 9 | Dec 18 | Dec 21 | Dec 25 | Dec 29 | Jan 1 | Jan 5 | Jan 12 | Jan 29 |
| 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 | 312 | 295 | 285 | 277 | 267 | 259 | 250 | 239 | 224 |
| 32°F | 365 | 359 | 351 | 343 | 335 | 328 | 319 | 307 | 294 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 358 | 347 |
| 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
- 100% of years
- 32°F or colder
- 81% of years
- 28°F or colder
- 27% of years
- 24°F or colder
- 2% 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
- 2,248
- Cooling degree days, base 65°F
- 168
- Growing degree days, base 40°F
- 7,046
- Growing degree days, base 45°F
- 5,226
- Growing degree days, base 50°F
- 3,461
- Growing degree days, base 55°F
- 1,895
- Growing degree days, base 60°F
- 735
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 343 | 0 | 141 |
| February | 291 | 1 | 142 |
| March | 261 | 2 | 210 |
| April | 221 | 5 | 235 |
| May | 165 | 7 | 307 |
| June | 107 | 11 | 354 |
| July | 56 | 25 | 434 |
| August | 43 | 33 | 454 |
| September | 48 | 43 | 446 |
| October | 107 | 32 | 391 |
| November | 225 | 9 | 238 |
| December | 381 | 0 | 109 |
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 1.8 km from Lompoc. 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 USC00045064 (Lompoc). Public domain.