Dewey climate

Dewey Frost Dates and Growing Season

NOAA 1991-2020 normals for Bartlesville F P Fld, 8.7 km from Dewey, elevation 715 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bartlesville F P Fld. 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 12 and the first fall freeze around October 21, a growing season of about 192 days.

Median at 36°F
last April 23, first October 12
Median at 32°F
last April 12, first October 21
Median at 28°F
last March 31, first October 31

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 6May 3Apr 30Apr 26Apr 23Apr 20Apr 17Apr 13Apr 9
32°FApr 28Apr 23Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2Mar 28
28°FApr 16Apr 10Apr 7Apr 3Mar 31Mar 29Mar 25Mar 21Mar 14
24°FApr 6Mar 31Mar 28Mar 24Mar 21Mar 17Mar 13Mar 9Mar 2
20°FMar 25Mar 19Mar 15Mar 12Mar 8Mar 4Mar 2Feb 27Feb 20
16°FMar 16Mar 10Mar 5Mar 2Feb 27Feb 24Feb 19Feb 14Feb 6

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 28Oct 3Oct 6Oct 9Oct 12Oct 14Oct 17Oct 21Oct 26
32°FOct 5Oct 11Oct 15Oct 19Oct 21Oct 24Oct 27Oct 30Nov 3
28°FOct 14Oct 21Oct 25Oct 28Oct 31Nov 2Nov 5Nov 9Nov 14
24°FOct 24Oct 31Nov 3Nov 6Nov 9Nov 12Nov 15Nov 20Nov 25
20°FNov 1Nov 7Nov 12Nov 15Nov 19Nov 23Nov 27Dec 1Dec 6
16°FNov 10Nov 17Nov 23Nov 27Dec 1Dec 4Dec 9Dec 14Dec 21

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°F192184179174170165162157151
32°F212205201196192187182177170
28°F234227220217213209205199190
24°F258250244239234230225219210
20°F278271266260255251247240231
16°F304295289283278273267261252

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
4,137
Cooling degree days, base 65°F
1,687
Growing degree days, base 40°F
7,266
Growing degree days, base 45°F
5,864
Growing degree days, base 50°F
4,609
Growing degree days, base 55°F
3,494
Growing degree days, base 60°F
2,521

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January93907
February717126
March5127110
April24032270
May68132530
June2334781
July0484949
August0443908
September32211629
October22741305
November537383
December860013

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 8.7 km from Dewey. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00003959 (Bartlesville F P Fld). Public domain.