Red Oak climate

Red Oak Frost Dates and Growing Season

NOAA 1991-2020 normals for Red Oak, 1.6 km from Red Oak, elevation 1040 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Red Oak. 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 24 and the first fall freeze around October 13, a growing season of about 169 days.

Median at 36°F
last May 4, first October 3
Median at 32°F
last April 24, first October 13
Median at 28°F
last April 15, first October 23

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 18May 13May 9May 6May 4May 2Apr 29Apr 25Apr 21
32°FMay 8May 3Apr 30Apr 28Apr 24Apr 21Apr 18Apr 15Apr 10
28°FApr 29Apr 24Apr 21Apr 17Apr 15Apr 11Apr 8Apr 5Apr 1
24°FApr 19Apr 14Apr 10Apr 6Apr 3Mar 31Mar 29Mar 25Mar 17
20°FApr 9Apr 4Mar 31Mar 29Mar 26Mar 21Mar 17Mar 12Mar 7
16°FApr 1Mar 27Mar 23Mar 19Mar 15Mar 11Mar 8Mar 4Feb 28

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 19Sep 23Sep 28Sep 30Oct 3Oct 5Oct 8Oct 12Oct 16
32°FSep 26Oct 1Oct 6Oct 10Oct 13Oct 16Oct 19Oct 22Oct 25
28°FOct 7Oct 14Oct 18Oct 20Oct 23Oct 25Oct 28Oct 31Nov 3
24°FOct 18Oct 23Oct 26Oct 30Nov 1Nov 3Nov 6Nov 10Nov 15
20°FOct 26Nov 1Nov 4Nov 6Nov 9Nov 11Nov 15Nov 20Nov 27
16°FNov 3Nov 8Nov 12Nov 15Nov 19Nov 22Nov 27Dec 1Dec 7

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°F169164159155151148145139132
32°F189182177173169165161156149
28°F211204199194190186181176170
24°F231224217213209205201196188
20°F254245238233229225220214207
16°F272264258253249243237231223

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
6,205
Cooling degree days, base 65°F
1,057
Growing degree days, base 40°F
5,638
Growing degree days, base 45°F
4,478
Growing degree days, base 50°F
3,441
Growing degree days, base 55°F
2,521
Growing degree days, base 60°F
1,726

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,31300
February1,06103
March798237
April4379134
May16171384
June16229663
July2340803
August6275735
September92116477
October38316183
November779024
December1,15801

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 1.6 km from Red Oak. 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 USC00136940 (Red Oak). Public domain.