Tyndall climate

Tyndall Frost Dates and Growing Season

NOAA 1991-2020 normals for Tyndall, 0.6 km from Tyndall, elevation 1420 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tyndall. 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 May 1 and the first fall freeze around October 7, a growing season of about 158 days.

Median at 36°F
last May 10, first September 30
Median at 32°F
last May 1, first October 7
Median at 28°F
last April 21, first October 17

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°FMay 22May 18May 15May 12May 10May 7May 5May 2Apr 29
32°FMay 14May 9May 6May 3May 1Apr 29Apr 26Apr 23Apr 18
28°FMay 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 15Apr 12Apr 7
24°FApr 26Apr 21Apr 17Apr 14Apr 10Apr 8Apr 5Apr 3Mar 30
20°FApr 18Apr 13Apr 9Apr 5Apr 3Apr 1Mar 29Mar 22Mar 17
16°FApr 10Apr 5Apr 2Mar 31Mar 26Mar 22Mar 18Mar 13Mar 9

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°FSep 17Sep 21Sep 24Sep 27Sep 30Oct 1Oct 4Oct 8Oct 12
32°FSep 24Sep 28Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20
28°FOct 1Oct 6Oct 10Oct 14Oct 17Oct 20Oct 22Oct 25Oct 29
24°FOct 13Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 9
20°FOct 22Oct 26Oct 29Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17
16°FOct 30Nov 3Nov 7Nov 9Nov 12Nov 15Nov 18Nov 22Nov 27

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°F157152147144140137134129123
32°F176170165161158154151146139
28°F196190185181177173169164157
24°F217211206202197193189184177
20°F236228223218214210206201194
16°F252246239234230226221215209

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
100% of years
20°F or colder
100% of years
16°F or colder
100% 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
7,256
Cooling degree days, base 65°F
833
Growing degree days, base 40°F
4,953
Growing degree days, base 45°F
3,889
Growing degree days, base 50°F
2,941
Growing degree days, base 55°F
2,115
Growing degree days, base 60°F
1,412

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,43200
February1,16901
March946118
April566377
May24642291
June39173584
July6296755
August15227677
September13585409
October4977116
November908013
December1,29900

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 0.6 km from Tyndall. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00398472 (Tyndall). Public domain.