Gumlog climate

Gumlog Frost Dates and Growing Season

NOAA 1991-2020 normals for Hartwell, 21.8 km from Gumlog, elevation 805 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hartwell. 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 20 and the first fall freeze around November 15, a growing season of about 241 days.

Median at 36°F
last April 3, first November 4
Median at 32°F
last March 20, first November 15
Median at 28°F
last March 7, first December 1

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 19Apr 13Apr 9Apr 6Apr 3Mar 31Mar 27Mar 23Mar 16
32°FApr 6Apr 1Mar 27Mar 24Mar 20Mar 17Mar 13Mar 8Mar 1
28°FMar 25Mar 20Mar 15Mar 11Mar 7Mar 2Feb 27Feb 21Feb 13
24°FMar 15Mar 9Mar 2Feb 26Feb 20Feb 13Feb 6Jan 31Jan 21
20°FMar 6Feb 27Feb 15Feb 7Feb 1Jan 28Jan 21Jan 14Jan 3
16°FFeb 24Feb 10Feb 2Jan 30Jan 22Jan 17Jan 12Jan 6Dec 29

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 22Oct 27Oct 31Nov 1Nov 4Nov 6Nov 10Nov 14Nov 19
32°FNov 1Nov 5Nov 8Nov 11Nov 15Nov 19Nov 23Nov 29Dec 5
28°FNov 10Nov 15Nov 19Nov 25Dec 1Dec 4Dec 9Dec 17Dec 29
24°FNov 24Dec 1Dec 5Dec 11Dec 19Dec 25Dec 31Jan 5Jan 13
20°FDec 8Dec 18Dec 26Dec 31Jan 3Jan 8Jan 14Jan 20Feb 1
16°FDec 23Dec 30Jan 3Jan 7Jan 13Jan 16Jan 22Jan 29Feb 9

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°F239231225221217213208203197
32°F270259252247241236231225216
28°F300290282275269265258252242
24°F336325316308302297289281270
20°F365357346338332324315306296
16°F365365365365359350340331317

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
99% of years
20°F or colder
89% of years
16°F or colder
56% 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
3,004
Cooling degree days, base 65°F
1,688
Growing degree days, base 40°F
7,976
Growing degree days, base 45°F
6,382
Growing degree days, base 50°F
4,950
Growing degree days, base 55°F
3,692
Growing degree days, base 60°F
2,604

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January699031
February545045
March3877159
April16540335
May37155583
June2335783
July0446911
August0409874
September9240681
October14150380
November4015124
December619045

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 21.8 km from Gumlog. 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 USC00094133 (Hartwell). Public domain.