Lincoln County climate

Lincoln County Frost Dates and Growing Season

NOAA 1991-2020 normals for Merrill, 18.6 km from Lincoln County, elevation 1250 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Merrill. 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 May 11 and the first fall freeze around September 30, a growing season of about 139 days.

Median at 36°F
last May 24, first September 20
Median at 32°F
last May 11, first September 30
Median at 28°F
last May 2, first October 10

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°FJun 6Jun 2May 30May 27May 24May 22May 19May 16May 11
32°FMay 27May 21May 18May 15May 11May 9May 6May 3Apr 29
28°FMay 16May 11May 7May 4May 2Apr 30Apr 27Apr 23Apr 19
24°FMay 5Apr 30Apr 27Apr 24Apr 22Apr 19Apr 16Apr 12Apr 6
20°FApr 25Apr 20Apr 17Apr 14Apr 10Apr 7Apr 4Apr 1Mar 28
16°FApr 17Apr 11Apr 7Apr 5Apr 3Mar 31Mar 29Mar 25Mar 19

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 5Sep 11Sep 15Sep 18Sep 20Sep 23Sep 26Sep 30Oct 3
32°FSep 17Sep 21Sep 25Sep 27Sep 30Oct 2Oct 5Oct 8Oct 12
28°FSep 26Oct 1Oct 4Oct 6Oct 10Oct 13Oct 16Oct 19Oct 25
24°FOct 6Oct 13Oct 17Oct 20Oct 23Oct 26Oct 30Nov 1Nov 5
20°FOct 21Oct 26Oct 30Nov 1Nov 2Nov 5Nov 8Nov 12Nov 17
16°FNov 1Nov 3Nov 6Nov 10Nov 13Nov 15Nov 18Nov 22Nov 27

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°F13713012512111811411010598
32°F157151147143139135131127120
28°F178171167163160155152147139
24°F202195191185182177173168160
20°F226218213209204200196191184
16°F242235230227223219215210203

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
8,667
Cooling degree days, base 65°F
373
Growing degree days, base 40°F
3,839
Growing degree days, base 45°F
2,900
Growing degree days, base 50°F
2,079
Growing degree days, base 55°F
1,375
Growing degree days, base 60°F
797

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,62100
February1,37600
March1,15206
April713130
May34119198
June9281441
July32145578
August5696505
September24030264
October624254
November1,00803
December1,41400

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 18.6 km from Lincoln County. 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 USC00475364 (Merrill). Public domain.