Red Oak climate

Red Oak Frost Dates and Growing Season

NOAA 1991-2020 normals for Rocky Mt Wilson AP, 20.5 km from Red Oak, elevation 160 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rocky Mt Wilson AP. 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 1 and the first fall freeze around November 5, a growing season of about 219 days.

Median at 36°F
last April 13, first October 28
Median at 32°F
last April 1, first November 5
Median at 28°F
last March 21, first November 16

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 1Apr 24Apr 19Apr 16Apr 13Apr 10Apr 7Apr 3Mar 30
32°FApr 16Apr 11Apr 7Apr 4Apr 1Mar 30Mar 26Mar 22Mar 16
28°FApr 6Apr 1Mar 29Mar 25Mar 21Mar 18Mar 14Mar 9Mar 1
24°FMar 25Mar 19Mar 15Mar 11Mar 6Mar 2Feb 27Feb 21Feb 10
20°FMar 13Mar 6Mar 1Feb 25Feb 19Feb 13Feb 6Jan 31Jan 21
16°FMar 1Feb 20Feb 13Feb 6Jan 31Jan 27Jan 20Jan 13Jan 2

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 16Oct 20Oct 23Oct 26Oct 28Oct 30Nov 1Nov 4Nov 8
32°FOct 25Oct 29Nov 1Nov 3Nov 5Nov 7Nov 10Nov 14Nov 19
28°FNov 1Nov 6Nov 9Nov 12Nov 16Nov 19Nov 23Nov 29Dec 4
24°FNov 11Nov 18Nov 22Nov 27Dec 1Dec 5Dec 11Dec 20Jan 1
20°FNov 26Dec 1Dec 7Dec 15Dec 24Dec 30Jan 4Jan 11Jan 22
16°FDec 10Dec 22Dec 30Jan 3Jan 9Jan 14Jan 18Jan 27Feb 11

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°F217210206202197193188183176
32°F240233228223219216211206200
28°F268259252247241237232226219
24°F303292284276270264258251242
20°F339327318311306299290282271
16°F365365354346338333325315305

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
82% 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
3,271
Cooling degree days, base 65°F
1,681
Growing degree days, base 40°F
7,783
Growing degree days, base 45°F
6,246
Growing degree days, base 50°F
4,867
Growing degree days, base 55°F
3,647
Growing degree days, base 60°F
2,584

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January735038
February591248
March4448135
April19545316
May51149563
June2327775
July0457922
August0403868
September13229666
October16354365
November4285119
December649254

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 20.5 km from Red Oak. 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 USW00093759 (Rocky Mt Wilson AP). Public domain.