Langdon climate

Langdon Frost Dates and Growing Season

NOAA 1991-2020 normals for Langdon Exp Farm, 1.7 km from Langdon, elevation 1615 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Langdon Exp Farm. 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 17 and the first fall freeze around September 26, a growing season of about 132 days.

Median at 36°F
last May 26, first September 18
Median at 32°F
last May 17, first September 26
Median at 28°F
last May 7, first October 4

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 7Jun 3May 31May 29May 26May 24May 21May 18May 15
32°FMay 30May 26May 23May 20May 17May 14May 12May 9May 4
28°FMay 21May 15May 13May 10May 7May 4May 1Apr 28Apr 22
24°FMay 11May 6May 3Apr 30Apr 28Apr 24Apr 20Apr 17Apr 12
20°FMay 3Apr 29Apr 24Apr 20Apr 18Apr 15Apr 11Apr 8Apr 4
16°FApr 23Apr 18Apr 15Apr 12Apr 9Apr 7Apr 4Apr 1Mar 26

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 13Sep 16Sep 18Sep 20Sep 22Sep 24Sep 28
32°FSep 13Sep 18Sep 21Sep 23Sep 26Sep 28Oct 1Oct 3Oct 7
28°FSep 22Sep 27Sep 30Oct 1Oct 4Oct 6Oct 10Oct 14Oct 18
24°FSep 30Oct 4Oct 7Oct 11Oct 14Oct 17Oct 20Oct 24Oct 28
20°FOct 8Oct 14Oct 17Oct 21Oct 24Oct 27Oct 30Nov 2Nov 6
16°FOct 17Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 9Nov 13

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°F12912512011611311010610296
32°F150143139135132128125120114
28°F170163159155151147143139132
24°F189182177173169164160155149
20°F208202197192188184179175167
16°F224217212208205201197192185

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
10,360
Cooling degree days, base 65°F
249
Growing degree days, base 40°F
3,361
Growing degree days, base 45°F
2,504
Growing degree days, base 50°F
1,749
Growing degree days, base 55°F
1,109
Growing degree days, base 60°F
598

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,89900
February1,60900
March1,36701
April816018
May4139154
June14244358
July5693502
August7782470
September30120212
October753133
November1,23000
December1,69900

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 1.7 km from Langdon. 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 USC00324958 (Langdon Exp Farm). Public domain.