Radford climate

Radford Frost Dates and Growing Season

NOAA 1991-2020 normals for Radford 3 N, 7.7 km from Radford, elevation 1800 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Radford 3 N. 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 26 and the first fall freeze around October 18, a growing season of about 174 days.

Median at 36°F
last May 7, first October 9
Median at 32°F
last April 26, first October 18
Median at 28°F
last April 10, first October 28

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 23May 19May 14May 10May 7May 3Apr 30Apr 26Apr 21
32°FMay 16May 10May 5Apr 30Apr 26Apr 22Apr 18Apr 14Apr 10
28°FMay 3Apr 22Apr 17Apr 14Apr 10Apr 6Apr 3Mar 31Mar 26
24°FApr 10Apr 5Apr 3Mar 31Mar 28Mar 25Mar 21Mar 17Mar 11
20°FMar 30Mar 26Mar 21Mar 18Mar 15Mar 11Mar 7Mar 2Feb 23
16°FMar 20Mar 15Mar 10Mar 6Mar 2Feb 26Feb 20Feb 12Feb 3

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 25Sep 30Oct 3Oct 6Oct 9Oct 11Oct 14Oct 16Oct 21
32°FOct 6Oct 10Oct 13Oct 16Oct 18Oct 21Oct 23Oct 27Oct 31
28°FOct 14Oct 19Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 9
24°FOct 24Oct 29Nov 1Nov 3Nov 5Nov 8Nov 12Nov 16Nov 23
20°FNov 2Nov 7Nov 11Nov 14Nov 18Nov 23Nov 28Dec 3Dec 10
16°FNov 15Nov 24Nov 28Dec 1Dec 5Dec 10Dec 18Dec 25Jan 4

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°F175167162157153149144140133
32°F195188183178174170166160152
28°F221213207203199195189183174
24°F247238232227223219214209202
20°F276266260255248244238232225
16°F315302294287281275268260251

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
5,067
Cooling degree days, base 65°F
702
Growing degree days, base 40°F
5,546
Growing degree days, base 45°F
4,250
Growing degree days, base 50°F
3,124
Growing degree days, base 55°F
2,160
Growing degree days, base 60°F
1,353

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00903
February81609
March691039
April3744148
May16532341
June24137563
July4235696
August7202660
September7983456
October35910170
November649032
December89009

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 7.7 km from Radford. 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 USC00446999 (Radford 3 N). Public domain.