Roxboro climate

Roxboro Frost Dates and Growing Season

NOAA 1991-2020 normals for Roxboro 7 Ese, 10.2 km from Roxboro, elevation 710 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Roxboro 7 Ese. 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 15 and the first fall freeze around October 26, a growing season of about 194 days.

Median at 36°F
last April 26, first October 17
Median at 32°F
last April 15, first October 26
Median at 28°F
last April 2, first November 3

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

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 4Oct 8Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26Oct 30
32°FOct 12Oct 17Oct 20Oct 23Oct 26Oct 28Oct 31Nov 2Nov 6
28°FOct 21Oct 26Oct 29Nov 1Nov 3Nov 5Nov 8Nov 12Nov 19
24°FOct 31Nov 3Nov 6Nov 9Nov 12Nov 15Nov 20Nov 27Dec 3
20°FNov 9Nov 13Nov 18Nov 23Nov 28Dec 2Dec 7Dec 15Dec 26
16°FNov 23Nov 30Dec 4Dec 11Dec 18Dec 25Jan 1Jan 9Jan 19

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°F194187182177173170166160153
32°F217208203198194190186181174
28°F241232226222217213209203196
24°F268258251246241236231225218
20°F303290283276269264258253242
16°F334324317309303296289279268

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
98% 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
3,801
Cooling degree days, base 65°F
1,357
Growing degree days, base 40°F
7,034
Growing degree days, base 45°F
5,569
Growing degree days, base 50°F
4,273
Growing degree days, base 55°F
3,140
Growing degree days, base 60°F
2,169

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January812018
February664023
March516497
April24130265
May80109496
June8270713
July0397862
August1342806
September30173593
October22329288
November500385
December726129

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 10.2 km from Roxboro. 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 USC00317516 (Roxboro 7 Ese). Public domain.