Elkhorn City climate

Elkhorn City Frost Dates and Growing Season

NOAA 1991-2020 normals for Breaks Interstate Park, 5.4 km from Elkhorn City, elevation 1893 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Breaks Interstate Park. 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 22 and the first fall freeze around October 23, a growing season of about 182 days.

Median at 36°F
last May 2, first October 14
Median at 32°F
last April 22, first October 23
Median at 28°F
last April 9, first November 1

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 19May 12May 9May 6May 2Apr 30Apr 27Apr 24Apr 19
32°FMay 8May 2Apr 29Apr 25Apr 22Apr 20Apr 16Apr 13Apr 8
28°FApr 25Apr 19Apr 15Apr 12Apr 9Apr 6Apr 4Apr 1Mar 28
24°FApr 12Apr 6Apr 4Apr 1Mar 29Mar 27Mar 23Mar 19Mar 13
20°FMar 31Mar 28Mar 24Mar 20Mar 18Mar 14Mar 10Mar 4Feb 26
16°FMar 24Mar 18Mar 14Mar 10Mar 5Mar 1Feb 25Feb 19Feb 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°FOct 1Oct 6Oct 9Oct 11Oct 14Oct 16Oct 19Oct 23Oct 27
32°FOct 10Oct 14Oct 18Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4
28°FOct 19Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 8Nov 12
24°FOct 29Nov 2Nov 5Nov 7Nov 10Nov 13Nov 16Nov 20Nov 25
20°FNov 7Nov 11Nov 15Nov 19Nov 23Nov 27Dec 1Dec 5Dec 13
16°FNov 18Nov 26Nov 30Dec 3Dec 8Dec 12Dec 18Dec 24Dec 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°F181175171167163160156152146
32°F201195190186182178174169163
28°F223216212208204200196190183
24°F249240235230227223218214207
20°F279269262256251246241235228
16°F308298291285279274266260250

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
4,857
Cooling degree days, base 65°F
706
Growing degree days, base 40°F
5,730
Growing degree days, base 45°F
4,415
Growing degree days, base 50°F
3,261
Growing degree days, base 55°F
2,255
Growing degree days, base 60°F
1,392

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January99307
February80109
March650054
April35310180
May14740365
June20135565
July2221684
August4207668
September6183474
October3329197
November623042
December871016

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 5.4 km from Elkhorn City. 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 USC00440982 (Breaks Interstate Park). Public domain.