Yuma County climate

Yuma County Frost Dates and Growing Season

NOAA 1991-2020 normals for Wray, 20.5 km from Yuma County, elevation 3553 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wray. 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 7 and the first fall freeze around October 6, a growing season of about 151 days.

Median at 36°F
last May 16, first September 29
Median at 32°F
last May 7, first October 6
Median at 28°F
last April 29, first October 15

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 29May 25May 21May 18May 16May 14May 11May 8May 5
32°FMay 19May 15May 12May 9May 7May 4May 2Apr 30Apr 25
28°FMay 11May 7May 3May 1Apr 29Apr 26Apr 22Apr 19Apr 14
24°FMay 1Apr 27Apr 24Apr 20Apr 18Apr 15Apr 11Apr 7Apr 3
20°FApr 22Apr 17Apr 13Apr 10Apr 7Apr 4Mar 31Mar 27Mar 20
16°FApr 12Apr 7Apr 4Apr 1Mar 28Mar 24Mar 18Mar 13Mar 7

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 16Sep 21Sep 24Sep 26Sep 29Oct 1Oct 3Oct 5Oct 9
32°FSep 25Sep 29Oct 1Oct 4Oct 6Oct 8Oct 11Oct 13Oct 16
28°FOct 2Oct 6Oct 10Oct 12Oct 15Oct 16Oct 18Oct 20Oct 23
24°FOct 9Oct 13Oct 16Oct 19Oct 21Oct 23Oct 26Oct 29Nov 2
20°FOct 15Oct 20Oct 24Oct 28Oct 31Nov 2Nov 5Nov 9Nov 14
16°FOct 22Oct 29Nov 1Nov 4Nov 8Nov 12Nov 15Nov 20Nov 26

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°F150146142138134131127123116
32°F167162158154151148145140134
28°F185178174171167164160156150
24°F206199194190186182178173168
20°F226220214209205200196190184
16°F252243236231226220215209200

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
5,948
Cooling degree days, base 65°F
949
Growing degree days, base 40°F
5,402
Growing degree days, base 45°F
4,222
Growing degree days, base 50°F
3,192
Growing degree days, base 55°F
2,307
Growing degree days, base 60°F
1,562

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10501
February93103
March744031
April491296
May22640307
June34190607
July4342803
August9271727
September10799450
October4356144
November777023
December1,08601

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 20.5 km from Yuma County. 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 USC00059243 (Wray). Public domain.