Oak Hill climate

Oak Hill Frost Dates and Growing Season

NOAA 1991-2020 normals for Scottsmoor 2.5 Ssw, 15.1 km from Oak Hill, elevation 42 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Scottsmoor 2.5 Ssw. 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 February 10 and the first fall freeze around January 8, a growing season of about 327 days.

Median at 36°F
last February 26, first December 24
Median at 32°F
last February 10, first January 8
Median at 28°F
last January 31, first January 17

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°FMar 20Mar 14Mar 7Mar 2Feb 26Feb 20Feb 12Feb 5Jan 27
32°FMar 10Mar 1Feb 23Feb 17Feb 10Feb 4Jan 30Jan 18Jan 7
28°FMar 2Feb 20Feb 12Feb 4Jan 31Jan 24Jan 17Jan 10Jan 4
24°FFeb 17Feb 3Jan 31Jan 23Jan 15Jan 10Jan 7Jan 3Dec 31
20°F–––––––––
16°F–––––––––

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°FNov 29Dec 4Dec 11Dec 19Dec 24Dec 29Jan 3Jan 9Jan 19
32°FDec 14Dec 25Dec 30Jan 3Jan 8Jan 13Jan 19Jan 30Feb 9
28°FDec 28Jan 3Jan 7Jan 11Jan 17Jan 24Feb 1Feb 8Feb 20
24°FDec 29Jan 1Jan 5Jan 8Jan 13Jan 19Jan 27Feb 1Feb 13
20°F–––––––––
16°F–––––––––

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°F330317309301294288281275264
32°F365354342334327318311303291
28°F365365365365365356343330314
24°F365365365365365365365365353
20°F365365365365365365365365365
16°F365365365365365365365365365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
99% of years
32°F or colder
88% of years
28°F or colder
49% of years
24°F or colder
13% of years
20°F or colder
0% of years
16°F or colder
0% 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
672
Cooling degree days, base 65°F
3,039
Growing degree days, base 40°F
11,493
Growing degree days, base 45°F
9,677
Growing degree days, base 50°F
7,884
Growing degree days, base 55°F
6,152
Growing degree days, base 60°F
4,518

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January20732308
February14246333
March9786458
April19172603
May1308772
June0439889
July0512977
August0516981
September0439890
October7306764
November56130524
December14354385

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 15.1 km from Oak Hill. 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 USC00088051 (Scottsmoor 2.5 Ssw). Public domain.