Osage County climate

Osage County Frost Dates and Growing Season

NOAA 1991-2020 normals for Pawhuska, 6.4 km from Osage County, elevation 835 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pawhuska. 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 6 and the first fall freeze around October 29, a growing season of about 204 days.

Median at 36°F
last April 18, first October 19
Median at 32°F
last April 6, first October 29
Median at 28°F
last March 28, first November 6

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 4Apr 29Apr 25Apr 22Apr 18Apr 15Apr 12Apr 8Apr 2
32°FApr 23Apr 17Apr 12Apr 9Apr 6Apr 2Mar 31Mar 28Mar 21
28°FApr 11Apr 6Apr 2Mar 31Mar 28Mar 25Mar 20Mar 15Mar 8
24°FMar 31Mar 27Mar 22Mar 17Mar 14Mar 10Mar 6Mar 2Feb 25
20°FMar 20Mar 14Mar 10Mar 6Mar 3Feb 28Feb 25Feb 20Feb 13
16°FMar 12Mar 6Mar 2Feb 27Feb 23Feb 19Feb 14Feb 8Jan 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 3Oct 9Oct 13Oct 16Oct 19Oct 22Oct 25Oct 28Nov 1
32°FOct 13Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 11
28°FOct 21Oct 27Oct 31Nov 3Nov 6Nov 10Nov 13Nov 17Nov 22
24°FOct 31Nov 4Nov 8Nov 12Nov 15Nov 19Nov 24Nov 28Dec 3
20°FNov 7Nov 14Nov 19Nov 23Nov 27Dec 1Dec 4Dec 8Dec 14
16°FNov 19Nov 27Dec 1Dec 4Dec 9Dec 14Dec 18Dec 24Dec 31

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°F203196191187182177174168161
32°F226218213208204199194188180
28°F250241234229224219214209202
24°F270262255250246241235229220
20°F291282277271266262256250241
16°F319308301295288282276269261

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
3,704
Cooling degree days, base 65°F
1,877
Growing degree days, base 40°F
7,768
Growing degree days, base 45°F
6,306
Growing degree days, base 50°F
4,986
Growing degree days, base 55°F
3,807
Growing degree days, base 60°F
2,770

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January870015
February663136
March44214152
April19549322
May50155571
June2359807
July0512976
August0476941
September23246674
October17959362
November4806113
December802020

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 6.4 km from Osage 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 USC00346935 (Pawhuska). Public domain.