Mojave Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Mojave. 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 15 and the first fall freeze around November 17, a growing season of about 241 days.
- Median at 36°F
- last April 11, first November 5
- Median at 32°F
- last March 15, first November 17
- Median at 28°F
- last February 22, first November 30
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 | May 6 | Apr 30 | Apr 24 | Apr 18 | Apr 11 | Apr 4 | Mar 30 | Mar 22 | Mar 12 |
| 32°F | Apr 17 | Apr 6 | Mar 29 | Mar 21 | Mar 15 | Mar 10 | Mar 4 | Feb 28 | Feb 21 |
| 28°F | Mar 22 | Mar 10 | Mar 4 | Feb 28 | Feb 22 | Feb 18 | Feb 13 | Feb 3 | Jan 25 |
| 24°F | Feb 26 | Feb 17 | Feb 10 | Feb 3 | Jan 30 | Jan 23 | Jan 16 | Jan 8 | Dec 30 |
| 20°F | Feb 12 | Feb 3 | Jan 25 | Jan 16 | Jan 11 | Jan 4 | Dec 31 | Dec 26 | Dec 16 |
| 16°F | Feb 5 | Jan 22 | Jan 13 | Jan 8 | Jan 4 | Jan 1 | Dec 29 | Dec 23 | Dec 13 |
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 22 | Oct 27 | Oct 31 | Nov 3 | Nov 5 | Nov 8 | Nov 10 | Nov 14 | Nov 19 |
| 32°F | Oct 31 | Nov 6 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 1 |
| 28°F | Nov 12 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 10 | Dec 16 |
| 24°F | Nov 26 | Dec 2 | Dec 6 | Dec 9 | Dec 13 | Dec 17 | Dec 22 | Dec 29 | Jan 8 |
| 20°F | Dec 7 | Dec 12 | Dec 18 | Dec 24 | Dec 28 | Jan 1 | Jan 6 | Jan 13 | Jan 30 |
| 16°F | Dec 11 | Dec 16 | Dec 27 | Dec 30 | Jan 2 | Jan 5 | Jan 10 | Jan 14 | Feb 2 |
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 | 237 | 227 | 219 | 214 | 208 | 202 | 194 | 186 | 177 |
| 32°F | 270 | 261 | 254 | 247 | 241 | 234 | 227 | 220 | 211 |
| 28°F | 312 | 301 | 293 | 285 | 279 | 273 | 267 | 260 | 248 |
| 24°F | 353 | 343 | 335 | 329 | 321 | 314 | 307 | 297 | 285 |
| 20°F | 365 | 365 | 365 | 363 | 356 | 349 | 340 | 333 | 323 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 355 |
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
- 96% of years
- 20°F or colder
- 63% of years
- 16°F or colder
- 20% 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
- 2,902
- Cooling degree days, base 65°F
- 2,018
- Growing degree days, base 40°F
- 8,291
- Growing degree days, base 45°F
- 6,633
- Growing degree days, base 50°F
- 5,174
- Growing degree days, base 55°F
- 3,933
- Growing degree days, base 60°F
- 2,891
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 609 | 0 | 19 |
| February | 486 | 0 | 41 |
| March | 362 | 3 | 150 |
| April | 218 | 22 | 266 |
| May | 79 | 141 | 529 |
| June | 9 | 375 | 816 |
| July | 0 | 563 | 1,028 |
| August | 0 | 533 | 998 |
| September | 8 | 309 | 751 |
| October | 106 | 72 | 433 |
| November | 379 | 1 | 128 |
| December | 646 | 0 | 14 |
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 1.2 km from Mojave. 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 USC00045756 (Mojave). Public domain.