Wheatland climate

Wheatland Frost Dates and Growing Season

NOAA 1991-2020 normals for Wheatland 4 N, 6.3 km from Wheatland, elevation 4638 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wheatland 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 19 and the first fall freeze around September 22, a growing season of about 125 days.

Median at 36°F
last June 1, first September 12
Median at 32°F
last May 19, first September 22
Median at 28°F
last May 9, first October 1

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 20Jun 12Jun 7Jun 4Jun 1May 29May 26May 23May 18
32°FJun 2May 28May 24May 22May 19May 16May 14May 10May 7
28°FMay 22May 17May 13May 11May 9May 6May 4May 1Apr 27
24°FMay 12May 7May 4May 2Apr 30Apr 27Apr 24Apr 20Apr 15
20°FMay 3Apr 28Apr 24Apr 20Apr 16Apr 13Apr 10Apr 6Apr 1
16°FApr 24Apr 17Apr 12Apr 8Apr 4Apr 1Mar 29Mar 24Mar 15

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°FAug 28Sep 2Sep 6Sep 10Sep 12Sep 15Sep 18Sep 21Sep 26
32°FSep 8Sep 13Sep 16Sep 19Sep 22Sep 25Sep 28Oct 1Oct 4
28°FSep 17Sep 22Sep 26Sep 29Oct 1Oct 3Oct 6Oct 10Oct 14
24°FSep 27Oct 1Oct 5Oct 8Oct 10Oct 13Oct 16Oct 19Oct 24
20°FOct 5Oct 11Oct 14Oct 17Oct 20Oct 23Oct 25Oct 28Nov 2
16°FOct 14Oct 18Oct 22Oct 25Oct 28Oct 31Nov 3Nov 7Nov 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°F12111511010610298938879
32°F142137133129125121117111104
28°F162155151147143140136131125
24°F182176171167163159155150142
20°F207199194189185181177171164
16°F229221215210204199194189181

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
6,373
Cooling degree days, base 65°F
565
Growing degree days, base 40°F
4,674
Growing degree days, base 45°F
3,520
Growing degree days, base 50°F
2,546
Growing degree days, base 55°F
1,735
Growing degree days, base 60°F
1,075

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08701
February95703
March783022
April569152
May31510202
June7485462
July8231688
August17187636
September14949360
October504298
November809020
December1,10003

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 6.3 km from Wheatland. 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 USC00489615 (Wheatland 4 N). Public domain.