Weeki Wachee Gardens Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Weeki Wachee. 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 February 5 and the first fall freeze around January 1, a growing season of about 322 days.
- Median at 36°F
- last February 23, first December 9
- Median at 32°F
- last February 5, first January 1
- Median at 28°F
- last January 24, first January 9
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 23 | Mar 14 | Mar 6 | Mar 1 | Feb 23 | Feb 17 | Feb 11 | Feb 4 | Jan 26 |
| 32°F | Mar 5 | Feb 25 | Feb 18 | Feb 12 | Feb 5 | Jan 31 | Jan 26 | Jan 17 | Jan 6 |
| 28°F | Feb 18 | Feb 9 | Feb 3 | Jan 31 | Jan 24 | Jan 17 | Jan 11 | Jan 5 | Dec 27 |
| 24°F | Feb 14 | Feb 2 | Jan 31 | Jan 22 | Jan 17 | Jan 10 | Jan 5 | Jan 1 | Dec 27 |
| 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 21 | Nov 30 | Dec 4 | Dec 9 | Dec 17 | Dec 25 | Jan 2 | Jan 13 |
| 32°F | Dec 1 | Dec 8 | Dec 18 | Dec 24 | Jan 1 | Jan 4 | Jan 10 | Jan 17 | Feb 1 |
| 28°F | Dec 13 | Dec 24 | Dec 31 | Jan 4 | Jan 9 | Jan 14 | Jan 22 | Jan 31 | Feb 9 |
| 24°F | Dec 19 | Dec 29 | Jan 2 | Jan 6 | Jan 11 | Jan 17 | Jan 24 | Feb 1 | Feb 11 |
| 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 | 326 | 313 | 305 | 297 | 290 | 282 | 275 | 266 | 253 |
| 32°F | 365 | 347 | 337 | 331 | 322 | 315 | 307 | 299 | 288 |
| 28°F | 365 | 365 | 365 | 365 | 357 | 347 | 338 | 330 | 319 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 348 |
| 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
- 99% of years
- 32°F or colder
- 90% of years
- 28°F or colder
- 59% of years
- 24°F or colder
- 20% of years
- 20°F or colder
- 1% 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
- 676
- Cooling degree days, base 65°F
- 3,478
- Growing degree days, base 40°F
- 11,930
- Growing degree days, base 45°F
- 10,116
- Growing degree days, base 50°F
- 8,329
- Growing degree days, base 55°F
- 6,601
- Growing degree days, base 60°F
- 4,971
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 217 | 47 | 320 |
| February | 133 | 65 | 361 |
| March | 75 | 123 | 516 |
| April | 17 | 220 | 653 |
| May | 1 | 374 | 839 |
| June | 0 | 498 | 948 |
| July | 0 | 555 | 1,020 |
| August | 0 | 556 | 1,021 |
| September | 0 | 498 | 948 |
| October | 8 | 331 | 787 |
| November | 63 | 131 | 519 |
| December | 161 | 81 | 398 |
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 5.5 km from Weeki Wachee Gardens. 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 USC00089430 (Weeki Wachee). Public domain.