Lyman climate

Lyman Frost Dates and Growing Season

NOAA 1991-2020 normals for Greer, 11.2 km from Lyman, elevation 940 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greer. 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 7, a growing season of about 224 days.

Median at 36°F
last April 9, first October 29
Median at 32°F
last March 28, first November 7
Median at 28°F
last March 15, 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 25Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Mar 31Mar 24
32°FApr 14Apr 7Apr 4Apr 1Mar 28Mar 25Mar 21Mar 17Mar 10
28°FApr 3Mar 28Mar 22Mar 18Mar 15Mar 11Mar 6Mar 1Feb 22
24°FMar 22Mar 16Mar 12Mar 6Mar 1Feb 24Feb 19Feb 12Feb 1
20°FMar 11Mar 2Feb 24Feb 17Feb 9Feb 2Jan 29Jan 22Jan 10
16°FFeb 28Feb 15Feb 4Jan 30Jan 25Jan 20Jan 14Jan 7Dec 31

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 16Oct 20Oct 24Oct 27Oct 29Nov 1Nov 3Nov 5Nov 11
32°FOct 26Oct 30Nov 1Nov 5Nov 7Nov 11Nov 13Nov 18Nov 24
28°FNov 3Nov 7Nov 12Nov 16Nov 20Nov 24Nov 29Dec 3Dec 11
24°FNov 16Nov 24Nov 29Dec 3Dec 6Dec 11Dec 17Dec 26Jan 4
20°FDec 2Dec 9Dec 15Dec 22Dec 28Jan 2Jan 7Jan 13Jan 21
16°FDec 14Dec 25Dec 31Jan 4Jan 8Jan 13Jan 17Jan 24Feb 2

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°F222215210205201198194190182
32°F248240233229224220216210203
28°F278271263257251246240235226
24°F315305297290283277269261252
20°F348336330322316308301293282
16°F365365360351343336330321308

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
97% of years
16°F or colder
74% 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
3,019
Cooling degree days, base 65°F
1,720
Growing degree days, base 40°F
7,993
Growing degree days, base 45°F
6,407
Growing degree days, base 50°F
4,981
Growing degree days, base 55°F
3,723
Growing degree days, base 60°F
2,636

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January699032
February536150
March3879162
April16342338
May39160586
June2343790
July0457922
August0415880
September12239676
October15049371
November4054126
December626147

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 11.2 km from Lyman. 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 USW00003870 (Greer). Public domain.