Gunnison climate

Gunnison Frost Dates and Growing Season

NOAA 1991-2020 normals for Manti, 19.8 km from Gunnison, elevation 5740 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Manti. 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 11 and the first fall freeze around October 6, a growing season of about 146 days.

Median at 36°F
last May 28, first September 27
Median at 32°F
last May 11, first October 6
Median at 28°F
last April 26, first October 16

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 14Jun 8Jun 3May 31May 28May 24May 21May 17May 11
32°FJun 1May 25May 19May 15May 11May 7May 3Apr 30Apr 25
28°FMay 14May 7May 2Apr 29Apr 26Apr 22Apr 18Apr 14Apr 8
24°FApr 27Apr 19Apr 15Apr 12Apr 8Apr 4Apr 1Mar 27Mar 18
20°FApr 10Apr 3Mar 29Mar 24Mar 19Mar 13Mar 9Mar 5Feb 28
16°FMar 22Mar 11Mar 7Mar 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 14Sep 19Sep 22Sep 25Sep 27Sep 29Oct 1Oct 4Oct 8
32°FSep 24Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 16Oct 19
28°FOct 2Oct 6Oct 10Oct 13Oct 16Oct 19Oct 22Oct 25Oct 29
24°FOct 13Oct 18Oct 22Oct 25Oct 28Oct 31Nov 3Nov 7Nov 12
20°FOct 23Oct 29Nov 1Nov 5Nov 8Nov 12Nov 15Nov 18Nov 22
16°FNov 1Nov 6Nov 11Nov 15Nov 18Nov 21Nov 24Nov 28Dec 4

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°F141135130126122117113107101
32°F167160155150146142136130122
28°F194186180176171167163157148
24°F225217210205200195190184177
20°F258249242237231227220213203
16°F284275270266261256250243233

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
6,272
Cooling degree days, base 65°F
528
Growing degree days, base 40°F
4,612
Growing degree days, base 45°F
3,471
Growing degree days, base 50°F
2,504
Growing degree days, base 55°F
1,697
Growing degree days, base 60°F
1,040

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14100
February90901
March740010
April548049
May3079204
June8678445
July5225685
August8175632
September12740370
October4581100
November80108
December1,14500

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 19.8 km from Gunnison. 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 USC00425402 (Manti). Public domain.