Larimore climate

Larimore Frost Dates and Growing Season

NOAA 1991-2020 normals for Larimore 4SW, 7.2 km from Larimore, elevation 1152 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Larimore 4SW. 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 28, a growing season of about 139 days.

Median at 36°F
last May 21, first September 19
Median at 32°F
last May 11, first September 28
Median at 28°F
last May 2, first October 8

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 4May 30May 26May 23May 21May 18May 15May 11May 7
32°FMay 25May 20May 17May 14May 11May 8May 5May 2Apr 28
28°FMay 18May 12May 8May 4May 2Apr 30Apr 27Apr 24Apr 19
24°FMay 8May 2Apr 30Apr 27Apr 23Apr 21Apr 18Apr 15Apr 10
20°FApr 29Apr 23Apr 20Apr 17Apr 15Apr 12Apr 9Apr 7Apr 3
16°FApr 19Apr 15Apr 11Apr 9Apr 6Apr 4Apr 2Mar 31Mar 23

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 10Sep 14Sep 17Sep 19Sep 21Sep 23Sep 26Sep 29
32°FSep 16Sep 21Sep 24Sep 27Sep 28Sep 30Oct 3Oct 6Oct 11
28°FSep 26Sep 30Oct 2Oct 5Oct 8Oct 10Oct 13Oct 17Oct 21
24°FOct 3Oct 7Oct 11Oct 15Oct 17Oct 20Oct 23Oct 26Oct 31
20°FOct 12Oct 17Oct 21Oct 24Oct 28Oct 31Nov 2Nov 6Nov 10
16°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 7Nov 9Nov 13Nov 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°F137132128124120117113108101
32°F156150146142139136132128122
28°F176170165160157153149145138
24°F196189185181177173169164157
20°F213207203200196192188183176
16°F229222217213210207203199192

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
9,546
Cooling degree days, base 65°F
375
Growing degree days, base 40°F
3,752
Growing degree days, base 45°F
2,855
Growing degree days, base 50°F
2,058
Growing degree days, base 55°F
1,362
Growing degree days, base 60°F
794

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,82700
February1,50600
March1,27401
April759027
May35517198
June9979432
July32142575
August54106518
September24628258
October679249
November1,13202
December1,58300

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 7.2 km from Larimore. 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 USC00325013 (Larimore 4SW). Public domain.