Winsted climate

Winsted Frost Dates and Growing Season

NOAA 1991-2020 normals for Barkhamsted, 8 km from Winsted, elevation 710 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Barkhamsted. 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 17, a growing season of about 168 days.

Median at 36°F
last May 12, first October 6
Median at 32°F
last April 30, first October 17
Median at 28°F
last April 16, first October 29

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 25May 21May 18May 15May 12May 9May 5May 2Apr 29
32°FMay 15May 11May 6May 3Apr 30Apr 28Apr 25Apr 21Apr 17
28°FMay 2Apr 27Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 3
24°FApr 17Apr 11Apr 8Apr 6Apr 3Apr 2Mar 31Mar 28Mar 22
20°FApr 6Apr 3Mar 31Mar 29Mar 26Mar 22Mar 19Mar 16Mar 11
16°FMar 30Mar 26Mar 22Mar 20Mar 17Mar 14Mar 11Mar 7Mar 3

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 24Sep 28Oct 1Oct 4Oct 6Oct 8Oct 11Oct 14Oct 20
32°FOct 4Oct 7Oct 11Oct 14Oct 17Oct 20Oct 24Oct 27Nov 2
28°FOct 13Oct 19Oct 23Oct 26Oct 29Nov 1Nov 4Nov 7Nov 11
24°FOct 25Oct 30Nov 2Nov 5Nov 9Nov 12Nov 16Nov 20Nov 26
20°FNov 5Nov 12Nov 16Nov 19Nov 22Nov 26Nov 29Dec 2Dec 8
16°FNov 18Nov 22Nov 27Nov 30Dec 2Dec 5Dec 9Dec 13Dec 21

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°F165159155151147144140136130
32°F189183177172168164160155147
28°F213207202198195190185180173
24°F240233227223219215210206199
20°F262256250246241237232226220
16°F284277270266261257252247240

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
6,553
Cooling degree days, base 65°F
591
Growing degree days, base 40°F
4,760
Growing degree days, base 45°F
3,650
Growing degree days, base 50°F
2,681
Growing degree days, base 55°F
1,843
Growing degree days, base 60°F
1,145

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28000
February1,09301
March935012
April553460
May25221253
June49105506
July5220680
August12169621
September11868402
October4244125
November750019
December1,08201

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 8 km from Winsted. 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 USC00060299 (Barkhamsted). Public domain.