Levan climate

Levan Frost Dates and Growing Season

NOAA 1991-2020 normals for Levan, 0.3 km from Levan, elevation 5298 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Levan. 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 May 10 and the first fall freeze around October 7, a growing season of about 148 days.

Median at 36°F
last May 26, first September 27
Median at 32°F
last May 10, first October 7
Median at 28°F
last April 27, first October 18

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 12Jun 6Jun 2May 30May 26May 21May 18May 14May 9
32°FMay 31May 23May 18May 14May 10May 6May 3Apr 30Apr 26
28°FMay 13May 6May 3Apr 30Apr 27Apr 25Apr 21Apr 17Apr 12
24°FMay 1Apr 24Apr 20Apr 15Apr 11Apr 7Apr 2Mar 29Mar 18
20°FApr 10Apr 4Mar 30Mar 24Mar 19Mar 14Mar 10Mar 6Feb 28
16°FMar 21Mar 13Mar 8Mar 4Mar 1Feb 27Feb 23Feb 18Feb 12

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 13Sep 18Sep 22Sep 25Sep 27Sep 30Oct 1Oct 5Oct 10
32°FSep 24Sep 29Oct 1Oct 4Oct 7Oct 10Oct 13Oct 17Oct 21
28°FOct 3Oct 8Oct 12Oct 15Oct 18Oct 21Oct 24Oct 27Nov 1
24°FOct 14Oct 19Oct 23Oct 26Oct 30Nov 2Nov 5Nov 9Nov 14
20°FOct 25Oct 31Nov 3Nov 6Nov 9Nov 12Nov 16Nov 19Nov 23
16°FNov 3Nov 9Nov 12Nov 16Nov 19Nov 22Nov 25Nov 27Dec 2

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°F143136132127122118114108100
32°F170163157152148143138132123
28°F193186181176172168164159150
24°F228217212206201196191185175
20°F258250244239232228222215207
16°F285277271266261256251245235

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
6,012
Cooling degree days, base 65°F
768
Growing degree days, base 40°F
5,063
Growing degree days, base 45°F
3,894
Growing degree days, base 50°F
2,891
Growing degree days, base 55°F
2,049
Growing degree days, base 60°F
1,344

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13900
February89301
March705016
April503166
May26716243
June63124513
July2303765
August4254714
September9568429
October4153133
November788011
December1,13700

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 0.3 km from Levan. 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 USC00425065 (Levan). Public domain.