Seminole climate

Seminole Frost Dates and Growing Season

NOAA 1991-2020 normals for Seminole, 1.5 km from Seminole, elevation 3336 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Seminole. 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 April 2 and the first fall freeze around November 6, a growing season of about 219 days.

Median at 36°F
last April 13, first October 29
Median at 32°F
last April 2, first November 6
Median at 28°F
last March 17, first November 16

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°FApr 27Apr 23Apr 19Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31
32°FApr 20Apr 12Apr 8Apr 4Apr 2Mar 30Mar 25Mar 20Mar 13
28°FApr 4Mar 31Mar 26Mar 21Mar 17Mar 13Mar 9Mar 5Feb 28
24°FMar 22Mar 15Mar 11Mar 7Mar 4Feb 28Feb 24Feb 19Feb 11
20°FMar 12Mar 5Mar 1Feb 23Feb 17Feb 11Feb 6Jan 31Jan 17
16°FMar 1Feb 20Feb 11Feb 5Jan 30Jan 21Jan 12Jan 4Dec 24

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°FOct 17Oct 21Oct 24Oct 27Oct 29Nov 1Nov 2Nov 5Nov 9
32°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 15Nov 20
28°FNov 1Nov 6Nov 10Nov 13Nov 16Nov 18Nov 22Nov 26Dec 1
24°FNov 11Nov 16Nov 20Nov 24Nov 26Nov 30Dec 3Dec 8Dec 15
20°FNov 20Nov 27Dec 1Dec 4Dec 9Dec 13Dec 19Dec 25Jan 4
16°FDec 1Dec 7Dec 13Dec 20Dec 24Dec 30Jan 4Jan 13Jan 30

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°F216210205201198193189184175
32°F241234228223219214209202195
28°F267258252246242237232225216
24°F296286279273268263258252243
20°F331319310303296290283276266
16°F365356347337330322313305294

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
88% 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
3,096
Cooling degree days, base 65°F
1,917
Growing degree days, base 40°F
8,182
Growing degree days, base 45°F
6,612
Growing degree days, base 50°F
5,190
Growing degree days, base 55°F
3,934
Growing degree days, base 60°F
2,846

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January711022
February534153
March3698176
April15647356
May39209637
June1410859
July0484949
August0454919
September17241674
October13761402
November4393118
December693027

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 1.5 km from Seminole. 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 USC00418201 (Seminole). Public domain.