Utopia climate

Utopia Frost Dates and Growing Season

NOAA 1991-2020 normals for Myakka Rvr SP, 7.1 km from Utopia, elevation 19 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Myakka Rvr SP. 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 1 and the first fall freeze around January 6, a growing season of about 336 days.

Median at 36°F
last February 19, first December 27
Median at 32°F
last February 1, first January 6
Median at 28°F
last January 15, 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.

Threshold10%20%30%40%50%60%70%80%90%
36°FMar 19Mar 10Mar 3Feb 24Feb 19Feb 12Feb 5Jan 30Jan 19
32°FMar 3Feb 20Feb 11Feb 5Feb 1Jan 27Jan 19Jan 10Jan 1
28°FFeb 10Feb 2Jan 30Jan 22Jan 15Jan 11Jan 7Jan 3Dec 29
24°FJan 31Jan 26Jan 17Jan 12Jan 9Jan 6Jan 2Dec 31Dec 23
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FNov 28Dec 4Dec 11Dec 21Dec 27Jan 1Jan 5Jan 12Jan 22
32°FDec 5Dec 21Dec 28Jan 2Jan 6Jan 10Jan 16Jan 26Feb 5
28°FDec 18Dec 30Jan 2Jan 6Jan 9Jan 12Jan 20Jan 30Feb 7
24°FDec 16Dec 30Jan 2Jan 5Jan 8Jan 10Jan 14Jan 23Jan 31
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F339328319311305298291283271
32°F365364355344336330323312301
28°F365365365365365365354342329
24°F365365365365365365365365365
20°F365365365365365365365365365
16°F365365365365365365365365365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
97% of years
32°F or colder
79% of years
28°F or colder
40% of years
24°F or colder
10% 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
417
Cooling degree days, base 65°F
3,581
Growing degree days, base 40°F
12,290
Growing degree days, base 45°F
10,467
Growing degree days, base 50°F
8,654
Growing degree days, base 55°F
6,872
Growing degree days, base 60°F
5,165

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January14560388
February8181422
March48139557
April8233675
May0383848
June0486936
July05441,009
August05601,025
September0494944
October4354815
November31154573
December10094463

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 7.1 km from Utopia. 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 USC00086065 (Myakka Rvr SP). Public domain.