Carrington climate

Carrington Frost Dates and Growing Season

NOAA 1991-2020 normals for Carrington 4 N, 6.6 km from Carrington, elevation 1560 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Carrington 4 N. 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 12 and the first fall freeze around September 27, a growing season of about 137 days.

Median at 36°F
last May 21, first September 20
Median at 32°F
last May 12, first September 27
Median at 28°F
last May 4, first October 5

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 2May 29May 26May 23May 21May 18May 16May 13May 9
32°FMay 25May 21May 17May 15May 12May 10May 7May 4Apr 30
28°FMay 17May 12May 9May 6May 4May 1Apr 29Apr 24Apr 19
24°FMay 8May 4May 1Apr 28Apr 23Apr 21Apr 17Apr 14Apr 10
20°FMay 1Apr 25Apr 20Apr 17Apr 14Apr 11Apr 8Apr 5Apr 2
16°FApr 21Apr 16Apr 13Apr 9Apr 6Apr 4Apr 2Mar 30Mar 20

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 8Sep 13Sep 15Sep 18Sep 20Sep 22Sep 24Sep 26Sep 30
32°FSep 17Sep 20Sep 22Sep 25Sep 27Sep 29Oct 1Oct 4Oct 9
28°FSep 24Sep 28Oct 1Oct 3Oct 5Oct 8Oct 12Oct 15Oct 19
24°FOct 2Oct 5Oct 10Oct 12Oct 15Oct 18Oct 22Oct 24Oct 29
20°FOct 12Oct 16Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 8
16°FOct 20Oct 26Oct 29Nov 1Nov 3Nov 6Nov 8Nov 12Nov 18

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°F138132128125121118114110103
32°F154149144141137134131127120
28°F173166162158155151147142136
24°F193187181177173170166161153
20°F211205201197193189183178170
16°F226221215212208204201197189

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
9,262
Cooling degree days, base 65°F
419
Growing degree days, base 40°F
3,903
Growing degree days, base 45°F
2,978
Growing degree days, base 50°F
2,159
Growing degree days, base 55°F
1,451
Growing degree days, base 60°F
864

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,75500
February1,46700
March1,22302
April722029
May34016202
June8581447
July24163604
August46125544
September22633279
October666149
November1,12502
December1,58400

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 6.6 km from Carrington. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00321362 (Carrington 4 N). Public domain.