Holt County climate

Holt County Frost Dates and Growing Season

NOAA 1991-2020 normals for O'neill, 10.5 km from Holt County, elevation 1990 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for O'neill. 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 3 and the first fall freeze around October 5, a growing season of about 155 days.

Median at 36°F
last May 12, first September 28
Median at 32°F
last May 3, first October 5
Median at 28°F
last April 23, 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 25May 21May 17May 14May 12May 9May 6May 4Apr 30
32°FMay 16May 11May 7May 5May 3May 1Apr 28Apr 23Apr 18
28°FMay 8May 3May 1Apr 27Apr 23Apr 20Apr 16Apr 12Apr 7
24°FApr 30Apr 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Mar 30
20°FApr 20Apr 13Apr 8Apr 5Apr 3Mar 31Mar 28Mar 23Mar 16
16°FApr 10Apr 5Apr 1Mar 29Mar 24Mar 21Mar 17Mar 13Mar 8

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 20Sep 23Sep 26Sep 28Sep 30Oct 2Oct 6Oct 10
32°FSep 22Sep 27Sep 29Oct 2Oct 5Oct 8Oct 11Oct 15Oct 19
28°FSep 29Oct 5Oct 8Oct 13Oct 15Oct 18Oct 20Oct 23Oct 28
24°FOct 9Oct 15Oct 19Oct 21Oct 24Oct 27Oct 30Nov 1Nov 6
20°FOct 20Oct 24Oct 28Oct 31Nov 1Nov 4Nov 7Nov 10Nov 16
16°FOct 27Oct 31Nov 3Nov 7Nov 10Nov 12Nov 16Nov 20Nov 25

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°F155148144141138135131126120
32°F176169164159155152148144139
28°F195188183179174170166160154
24°F216208203198194190185179170
20°F234226220215211207203197189
16°F250244238233229224219214205

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
7,109
Cooling degree days, base 65°F
835
Growing degree days, base 40°F
4,930
Growing degree days, base 45°F
3,856
Growing degree days, base 50°F
2,912
Growing degree days, base 55°F
2,094
Growing degree days, base 60°F
1,401

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35000
February1,12702
March918118
April573373
May26337274
June47164568
July7303761
August17235684
September14387405
October5086113
November899015
December1,25800

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 10.5 km from Holt 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 USC00256290 (O'neill). Public domain.