Meadowbrook Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Elsinore. 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 28 and the first fall freeze around December 18, a growing season of about 329 days.
- Median at 36°F
- last February 28, first December 2
- Median at 32°F
- last January 28, first December 18
- Median at 28°F
- last January 1, first December 27
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 2 | Mar 21 | Mar 12 | Mar 5 | Feb 28 | Feb 25 | Feb 18 | Feb 10 | Jan 29 |
| 32°F | Feb 27 | Feb 19 | Feb 10 | Feb 4 | Jan 28 | Jan 18 | Jan 9 | Jan 2 | Dec 24 |
| 28°F | Feb 9 | Jan 28 | Jan 13 | Jan 7 | Jan 1 | Dec 29 | Dec 25 | Dec 20 | Dec 12 |
| 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 15 | Nov 22 | Nov 27 | Nov 30 | Dec 2 | Dec 5 | Dec 9 | Dec 13 | Dec 18 |
| 32°F | Dec 1 | Dec 6 | Dec 10 | Dec 13 | Dec 18 | Dec 22 | Dec 28 | Jan 4 | Jan 24 |
| 28°F | Dec 9 | Dec 13 | Dec 18 | Dec 23 | Dec 27 | Dec 30 | Jan 4 | Jan 13 | Feb 3 |
| 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 | 307 | 295 | 286 | 280 | 274 | 268 | 261 | 251 | 240 |
| 32°F | 361 | 352 | 343 | 336 | 329 | 319 | 310 | 302 | 287 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 360 | 351 | 339 |
| 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
- 91% of years
- 28°F or colder
- 38% 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
- 1,610
- Cooling degree days, base 65°F
- 1,987
- Growing degree days, base 40°F
- 9,502
- Growing degree days, base 45°F
- 7,688
- Growing degree days, base 50°F
- 5,940
- Growing degree days, base 55°F
- 4,370
- Growing degree days, base 60°F
- 3,048
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 349 | 2 | 144 |
| February | 286 | 3 | 154 |
| March | 208 | 12 | 274 |
| April | 115 | 43 | 379 |
| May | 42 | 132 | 555 |
| June | 4 | 282 | 728 |
| July | 0 | 474 | 939 |
| August | 0 | 505 | 970 |
| September | 2 | 367 | 816 |
| October | 35 | 143 | 574 |
| November | 187 | 23 | 292 |
| December | 383 | 1 | 116 |
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 7.2 km from Meadowbrook. 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 USC00042805 (Elsinore). Public domain.