Prowers County climate

Prowers County Frost Dates and Growing Season

NOAA 1991-2020 normals for Holly, 25.3 km from Prowers County, elevation 3401 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Holly. 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 1 and the first fall freeze around October 12, a growing season of about 163 days.

Median at 36°F
last May 10, first October 3
Median at 32°F
last May 1, first October 12
Median at 28°F
last April 21, first October 21

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 25May 19May 16May 13May 10May 8May 6May 3Apr 30
32°FMay 14May 9May 6May 4May 1Apr 30Apr 26Apr 22Apr 18
28°FMay 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 16Apr 13Apr 7
24°FApr 25Apr 21Apr 17Apr 14Apr 10Apr 7Apr 4Mar 31Mar 25
20°FApr 17Apr 10Apr 6Apr 3Mar 31Mar 27Mar 22Mar 15Mar 9
16°FApr 6Apr 1Mar 26Mar 20Mar 15Mar 10Mar 6Mar 2Feb 26

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 23Sep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 11Oct 15
32°FSep 29Oct 3Oct 6Oct 9Oct 12Oct 15Oct 17Oct 20Oct 23
28°FOct 7Oct 12Oct 16Oct 18Oct 21Oct 23Oct 25Oct 28Nov 2
24°FOct 18Oct 22Oct 25Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11
20°FOct 25Oct 30Nov 2Nov 4Nov 7Nov 9Nov 13Nov 17Nov 21
16°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Nov 29

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°F161155152148145142138133126
32°F179174169166163159155150144
28°F199193188184181177173168162
24°F221214209205201197192187182
20°F244236231226222217212207199
16°F267259253247243237232226217

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
5,439
Cooling degree days, base 65°F
1,199
Growing degree days, base 40°F
5,956
Growing degree days, base 45°F
4,722
Growing degree days, base 50°F
3,636
Growing degree days, base 55°F
2,689
Growing degree days, base 60°F
1,878

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07001
February87104
March674041
April4154135
May16063382
June17246680
July1406869
August3336798
September72133516
October36111185
November732026
December1,06301

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 25.3 km from Prowers 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 USC00054076 (Holly). Public domain.