Apollo Beach Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Tampa Bay Area WFO. 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 January 9, a growing season of about 357 days.
- Median at 36°F
- last February 3, first January 1
- Median at 32°F
- last January 20, first January 9
- Median at 28°F
- last January 17, first January 14
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 6 | Feb 24 | Feb 16 | Feb 10 | Feb 3 | Jan 29 | Jan 23 | Jan 14 | Jan 6 |
| 32°F | Feb 16 | Feb 7 | Feb 1 | Jan 27 | Jan 20 | Jan 14 | Jan 9 | Jan 5 | Dec 31 |
| 28°F | Feb 7 | Feb 1 | Jan 29 | Jan 24 | Jan 17 | Jan 12 | Jan 8 | Jan 5 | Dec 31 |
| 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 | Dec 4 | Dec 12 | Dec 21 | Dec 28 | Jan 1 | Jan 6 | Jan 13 | Jan 22 | Feb 1 |
| 32°F | Dec 19 | Dec 28 | Jan 1 | Jan 5 | Jan 9 | Jan 14 | Jan 21 | Jan 27 | Feb 7 |
| 28°F | Dec 29 | Jan 2 | Jan 7 | Jan 9 | Jan 14 | Jan 20 | Jan 27 | Jan 31 | Feb 5 |
| 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 | 362 | 350 | 340 | 334 | 327 | 319 | 311 | 303 | 291 |
| 32°F | 365 | 365 | 365 | 365 | 357 | 349 | 340 | 332 | 320 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 364 | 344 |
| 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
- 91% of years
- 32°F or colder
- 54% of years
- 28°F or colder
- 17% 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
- 499
- Cooling degree days, base 65°F
- 3,477
- Growing degree days, base 40°F
- 12,104
- Growing degree days, base 45°F
- 10,283
- Growing degree days, base 50°F
- 8,475
- Growing degree days, base 55°F
- 6,709
- Growing degree days, base 60°F
- 5,027
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 170 | 54 | 362 |
| February | 99 | 69 | 393 |
| March | 53 | 130 | 543 |
| April | 10 | 227 | 668 |
| May | 1 | 379 | 843 |
| June | 0 | 480 | 930 |
| July | 0 | 533 | 998 |
| August | 0 | 541 | 1,006 |
| September | 0 | 486 | 936 |
| October | 5 | 344 | 804 |
| November | 42 | 147 | 555 |
| December | 121 | 87 | 437 |
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 7.6 km from Apollo Beach. 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 USC00088782 (Tampa Bay Area WFO). Public domain.