Ryan climate

Ryan Frost Dates and Growing Season

NOAA 1991-2020 normals for Waurika, 17.6 km from Ryan, elevation 912 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Waurika. 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 March 24 and the first fall freeze around November 8, a growing season of about 228 days.

Median at 36°F
last April 5, first October 31
Median at 32°F
last March 24, first November 8
Median at 28°F
last March 12, first November 19

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°FApr 22Apr 17Apr 12Apr 8Apr 5Apr 2Mar 30Mar 26Mar 19
32°FApr 8Apr 3Mar 30Mar 27Mar 24Mar 20Mar 16Mar 12Mar 5
28°FMar 30Mar 24Mar 19Mar 15Mar 12Mar 9Mar 4Feb 28Feb 21
24°FMar 16Mar 11Mar 7Mar 3Feb 27Feb 23Feb 18Feb 11Feb 1
20°FMar 9Mar 2Feb 25Feb 20Feb 14Feb 7Feb 1Jan 26Jan 17
16°FFeb 28Feb 19Feb 9Feb 1Jan 27Jan 22Jan 15Jan 4Dec 22

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 13Oct 21Oct 24Oct 28Oct 31Nov 1Nov 4Nov 8Nov 13
32°FOct 23Oct 30Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19Nov 26
28°FNov 1Nov 6Nov 11Nov 15Nov 19Nov 23Nov 28Dec 1Dec 6
24°FNov 10Nov 18Nov 24Nov 28Dec 1Dec 4Dec 8Dec 13Dec 19
20°FNov 25Dec 1Dec 6Dec 11Dec 15Dec 21Dec 26Jan 1Jan 10
16°FDec 4Dec 11Dec 18Dec 22Dec 28Jan 2Jan 8Jan 16Feb 1

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°F229221216211207203197192184
32°F254245238233228224219214204
28°F278269262258252247242235228
24°F307297289283278272266259249
20°F340328319311305299292283272
16°F365361352344336329321309298

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
99% of years
16°F or colder
84% 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
2,730
Cooling degree days, base 65°F
2,483
Growing degree days, base 40°F
9,058
Growing degree days, base 45°F
7,448
Growing degree days, base 50°F
5,983
Growing degree days, base 55°F
4,665
Growing degree days, base 60°F
3,497

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January679137
February499271
March30324239
April11379422
May19238684
June0455904
July06171,082
August05951,060
September8350792
October105109476
November36514172
December639145

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 17.6 km from Ryan. 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 USC00349395 (Waurika). Public domain.