Sunray climate

Sunray Frost Dates and Growing Season

NOAA 1991-2020 normals for Dumas, 20.8 km from Sunray, elevation 3655 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dumas. 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 21 and the first fall freeze around October 24, a growing season of about 183 days.

Median at 36°F
last May 2, first October 14
Median at 32°F
last April 21, first October 24
Median at 28°F
last April 10, first November 2

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 13May 8May 5May 2Apr 29Apr 26Apr 21Apr 16
32°FMay 9May 3Apr 30Apr 26Apr 21Apr 18Apr 14Apr 10Apr 4
28°FApr 30Apr 23Apr 18Apr 14Apr 10Apr 6Apr 3Mar 30Mar 23
24°FApr 19Apr 11Apr 6Apr 2Mar 31Mar 26Mar 21Mar 16Mar 10
20°FApr 7Mar 31Mar 25Mar 21Mar 16Mar 11Mar 7Mar 3Feb 26
16°FMar 23Mar 15Mar 10Mar 6Mar 2Feb 28Feb 23Feb 18Feb 10

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 30Oct 4Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27
32°FOct 5Oct 13Oct 18Oct 21Oct 24Oct 27Oct 29Nov 1Nov 5
28°FOct 15Oct 23Oct 28Oct 31Nov 2Nov 5Nov 7Nov 11Nov 15
24°FOct 26Nov 1Nov 5Nov 9Nov 11Nov 14Nov 18Nov 21Nov 26
20°FNov 2Nov 9Nov 14Nov 18Nov 21Nov 25Nov 28Dec 1Dec 6
16°FNov 11Nov 19Nov 24Nov 28Dec 1Dec 5Dec 8Dec 13Dec 19

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°F183176171166163158154148137
32°F204197192187183178173167160
28°F226218213207203200194188180
24°F249240234229224219213206199
20°F274265259252246241235229219
16°F299289282276271266260252244

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
4,479
Cooling degree days, base 65°F
1,428
Growing degree days, base 40°F
6,720
Growing degree days, base 45°F
5,345
Growing degree days, base 50°F
4,137
Growing degree days, base 55°F
3,088
Growing degree days, base 60°F
2,187

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91004
February735014
March564277
April33013196
May11999452
June8296738
July2425888
August3378840
September46184591
October27131269
November597163
December89606

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 20.8 km from Sunray. 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 USC00412617 (Dumas). Public domain.