Rowland climate

Rowland Frost Dates and Growing Season

NOAA 1991-2020 normals for Dillon, 15.4 km from Rowland, elevation 118 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dillon. 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 March 28 and the first fall freeze around November 8, a growing season of about 227 days.

Median at 36°F
last April 8, first October 31
Median at 32°F
last March 28, first November 8
Median at 28°F
last March 14, first November 20

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°FApr 24Apr 19Apr 15Apr 11Apr 8Apr 5Apr 2Mar 30Mar 23
32°FApr 12Apr 7Apr 3Apr 1Mar 28Mar 25Mar 20Mar 16Mar 9
28°FApr 2Mar 28Mar 23Mar 18Mar 14Mar 10Mar 5Feb 28Feb 20
24°FMar 18Mar 11Mar 6Mar 2Feb 25Feb 20Feb 13Feb 5Jan 30
20°FMar 6Feb 28Feb 19Feb 10Feb 4Jan 31Jan 25Jan 17Jan 5
16°FFeb 19Feb 8Feb 1Jan 27Jan 24Jan 18Jan 12Jan 3Dec 27

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 18Oct 22Oct 26Oct 28Oct 31Nov 1Nov 4Nov 7Nov 11
32°FOct 27Nov 1Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18Nov 25
28°FNov 4Nov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 2Dec 9
24°FNov 15Nov 21Nov 26Dec 1Dec 4Dec 9Dec 16Dec 27Jan 5
20°FNov 27Dec 4Dec 10Dec 19Dec 28Jan 1Jan 7Jan 14Jan 26
16°FDec 8Dec 18Dec 28Jan 1Jan 8Jan 13Jan 19Jan 24Feb 1

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°F225219214209205201197192185
32°F252243237231227222217211205
28°F280270264258253248242236227
24°F320306298291284277270263253
20°F357342334328320311304294282
16°F365365365363352343336330315

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
93% of years
16°F or colder
62% 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
2,752
Cooling degree days, base 65°F
1,950
Growing degree days, base 40°F
8,459
Growing degree days, base 45°F
6,839
Growing degree days, base 50°F
5,372
Growing degree days, base 55°F
4,067
Growing degree days, base 60°F
2,924

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January649151
February508266
March36512181
April14856366
May28188625
June2378826
July0498962
August0451916
September8275717
October11975426
November35911164
December567372

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 15.4 km from Rowland. 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 USC00382386 (Dillon). Public domain.