Goleta Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Santa Barbara Muni AP. 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 11 and the first fall freeze around December 16, a growing season of about 342 days.
- Median at 36°F
- last February 13, first December 1
- Median at 32°F
- last January 11, first December 16
- Median at 28°F
- last December 30, first December 26
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 17 | Mar 3 | Feb 26 | Feb 19 | Feb 13 | Feb 7 | Feb 1 | Jan 24 | Jan 9 |
| 32°F | Feb 13 | Feb 2 | Jan 28 | Jan 19 | Jan 11 | Jan 4 | Dec 31 | Dec 25 | Dec 14 |
| 28°F | Jan 18 | Jan 10 | Jan 4 | Jan 1 | Dec 30 | Dec 27 | Dec 19 | Dec 13 | Dec 8 |
| 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 11 | Nov 18 | Nov 24 | Nov 27 | Dec 1 | Dec 4 | Dec 7 | Dec 12 | Dec 20 |
| 32°F | Dec 1 | Dec 5 | Dec 8 | Dec 12 | Dec 16 | Dec 22 | Dec 29 | Jan 4 | Jan 18 |
| 28°F | Dec 7 | Dec 11 | Dec 18 | Dec 22 | Dec 26 | Dec 29 | Jan 1 | Jan 5 | Jan 12 |
| 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 | 324 | 313 | 304 | 298 | 290 | 283 | 275 | 267 | 255 |
| 32°F | 365 | 365 | 356 | 348 | 342 | 335 | 329 | 320 | 309 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 362 | 352 |
| 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
- 26% of years
- 24°F or colder
- 3% 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
- 2,292
- Cooling degree days, base 65°F
- 214
- Growing degree days, base 40°F
- 7,047
- Growing degree days, base 45°F
- 5,226
- Growing degree days, base 50°F
- 3,460
- Growing degree days, base 55°F
- 1,923
- Growing degree days, base 60°F
- 817
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 380 | 0 | 105 |
| February | 317 | 0 | 117 |
| March | 280 | 2 | 192 |
| April | 217 | 6 | 239 |
| May | 157 | 10 | 318 |
| June | 91 | 13 | 372 |
| July | 29 | 51 | 487 |
| August | 23 | 62 | 504 |
| September | 44 | 44 | 450 |
| October | 112 | 24 | 377 |
| November | 251 | 3 | 206 |
| December | 392 | 0 | 94 |
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 1.7 km from Goleta. 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 USW00023190 (Santa Barbara Muni AP). Public domain.