Denver City climate

Denver City Frost Dates and Growing Season

NOAA 1991-2020 normals for Denver City, 0.7 km from Denver City, elevation 3590 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Denver City. 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 7 and the first fall freeze around November 4, a growing season of about 209 days.

Median at 36°F
last April 19, first October 26
Median at 32°F
last April 7, first November 4
Median at 28°F
last March 24, first November 13

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 1Apr 27Apr 24Apr 21Apr 19Apr 16Apr 13Apr 8Apr 2
32°FApr 23Apr 17Apr 13Apr 10Apr 7Apr 4Apr 1Mar 28Mar 20
28°FApr 12Apr 5Apr 1Mar 29Mar 24Mar 20Mar 15Mar 10Mar 4
24°FMar 29Mar 22Mar 17Mar 13Mar 9Mar 6Mar 2Feb 26Feb 19
20°FMar 17Mar 10Mar 5Feb 28Feb 25Feb 19Feb 13Feb 5Jan 26
16°FMar 7Feb 28Feb 21Feb 11Feb 4Jan 29Jan 20Jan 10Dec 30

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 12Oct 17Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6
32°FOct 19Oct 25Oct 29Nov 1Nov 4Nov 6Nov 8Nov 12Nov 16
28°FOct 30Nov 4Nov 7Nov 11Nov 13Nov 16Nov 19Nov 22Nov 28
24°FNov 8Nov 14Nov 18Nov 22Nov 25Nov 28Dec 1Dec 4Dec 9
20°FNov 19Nov 26Nov 30Dec 2Dec 6Dec 10Dec 15Dec 21Dec 28
16°FNov 27Dec 4Dec 10Dec 15Dec 21Dec 25Jan 1Jan 9Jan 20

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°F208202197193188185181176169
32°F232223218213209205200194188
28°F257249242238232228223217209
24°F285277271265261256251244234
20°F319308301294288283278271262
16°F360348340332323314306298285

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
93% 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
3,265
Cooling degree days, base 65°F
1,666
Growing degree days, base 40°F
7,790
Growing degree days, base 45°F
6,239
Growing degree days, base 50°F
4,844
Growing degree days, base 55°F
3,615
Growing degree days, base 60°F
2,558

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January733020
February558147
March3986153
April18231316
May50169586
June1367816
July0434899
August0400865
September24207634
October15949372
November4522113
December707024

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 0.7 km from Denver 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 USC00412408 (Denver City). Public domain.