Garwin climate

Garwin Frost Dates and Growing Season

NOAA 1991-2020 normals for Toledo 3N, 10.2 km from Garwin, elevation 935 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Toledo 3N. 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 30 and the first fall freeze around October 9, a growing season of about 162 days.

Median at 36°F
last May 7, first September 30
Median at 32°F
last April 30, first October 9
Median at 28°F
last April 19, first October 20

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 20May 16May 12May 9May 7May 5May 3Apr 30Apr 27
32°FMay 11May 7May 4May 2Apr 30Apr 27Apr 23Apr 20Apr 15
28°FMay 3Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 5
24°FApr 24Apr 18Apr 14Apr 11Apr 8Apr 6Apr 3Mar 31Mar 25
20°FApr 14Apr 9Apr 5Apr 3Mar 31Mar 28Mar 24Mar 19Mar 14
16°FApr 5Apr 1Mar 28Mar 23Mar 20Mar 17Mar 14Mar 10Mar 5

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 2Oct 5Oct 7Oct 12
32°FSep 26Sep 30Oct 3Oct 6Oct 9Oct 12Oct 14Oct 18Oct 22
28°FOct 6Oct 12Oct 15Oct 17Oct 20Oct 22Oct 25Oct 27Nov 1
24°FOct 17Oct 21Oct 24Oct 27Oct 29Nov 1Nov 3Nov 6Nov 12
20°FOct 25Oct 30Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 24
16°FNov 1Nov 5Nov 8Nov 11Nov 15Nov 18Nov 22Nov 27Dec 3

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°F162156152148144141138134128
32°F181174169165162158154150144
28°F203195190186182178174169161
24°F223215210206202199195190183
20°F243234230224219215211206200
16°F262254247243239234229224216

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
7,115
Cooling degree days, base 65°F
704
Growing degree days, base 40°F
4,891
Growing degree days, base 45°F
3,811
Growing degree days, base 50°F
2,849
Growing degree days, base 55°F
2,004
Growing degree days, base 60°F
1,286

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,45400
February1,19401
March935119
April530385
May22342303
June32158576
July7238696
August19180626
September13473395
October4609132
November861016
December1,26501

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 10.2 km from Garwin. 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 USC00138296 (Toledo 3N). Public domain.