East Carbon City climate

East Carbon City Frost Dates and Growing Season

NOAA 1991-2020 normals for Sunnyside City, 2.2 km from East Carbon City, elevation 6511 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sunnyside City. 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 26 and the first fall freeze around October 25, a growing season of about 181 days.

Median at 36°F
last May 11, first October 12
Median at 32°F
last April 26, first October 25
Median at 28°F
last April 7, first November 7

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°FJun 2May 24May 20May 16May 11May 6May 2Apr 30Apr 25
32°FMay 18May 9May 2Apr 29Apr 26Apr 22Apr 18Apr 13Apr 8
28°FApr 26Apr 19Apr 15Apr 11Apr 7Apr 3Mar 31Mar 24Mar 15
24°FApr 8Mar 31Mar 25Mar 18Mar 14Mar 9Mar 5Mar 1Feb 20
20°FMar 16Mar 9Mar 5Mar 1Feb 26Feb 21Feb 16Feb 10Feb 1
16°FMar 3Feb 27Feb 20Feb 14Feb 9Feb 4Jan 28Jan 16Dec 31

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 27Oct 2Oct 5Oct 9Oct 12Oct 16Oct 19Oct 23Oct 29
32°FOct 7Oct 13Oct 18Oct 22Oct 25Oct 29Nov 1Nov 5Nov 11
28°FOct 22Oct 28Nov 1Nov 4Nov 7Nov 11Nov 15Nov 18Nov 22
24°FNov 1Nov 6Nov 10Nov 15Nov 18Nov 20Nov 24Nov 28Dec 4
20°FNov 9Nov 16Nov 21Nov 24Nov 28Dec 3Dec 7Dec 11Dec 18
16°FNov 19Nov 27Dec 2Dec 6Dec 10Dec 15Dec 20Dec 27Jan 8

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°F177168162157152147142135125
32°F206196191186181175170162153
28°F239229223218212207201195186
24°F276265257252246240232225215
20°F311297290283278270265257247
16°F345332320312306300292284274

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
97% 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
5,933
Cooling degree days, base 65°F
688
Growing degree days, base 40°F
4,888
Growing degree days, base 45°F
3,746
Growing degree days, base 50°F
2,773
Growing degree days, base 55°F
1,946
Growing degree days, base 60°F
1,250

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07900
February89400
March713013
April500060
May26416244
June56120516
July2269732
August7221679
September10558412
October4503112
November78006
December1,08400

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 2.2 km from East Carbon City. 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 USC00428476 (Sunnyside City). Public domain.