Tremonton climate

Tremonton Frost Dates and Growing Season

NOAA 1991-2020 normals for Tremonton, 0.2 km from Tremonton, elevation 4310 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tremonton. 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 April 24 and the first fall freeze around October 17, a growing season of about 175 days.

Median at 36°F
last May 6, first October 7
Median at 32°F
last April 24, first October 17
Median at 28°F
last April 9, first October 26

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°FMay 29May 18May 13May 9May 6May 3Apr 30Apr 28Apr 23
32°FMay 9May 3Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 8
28°FApr 26Apr 20Apr 17Apr 13Apr 9Apr 6Apr 3Mar 29Mar 20
24°FApr 10Apr 4Mar 31Mar 28Mar 22Mar 17Mar 14Mar 11Mar 6
20°FMar 26Mar 19Mar 14Mar 11Mar 8Mar 6Mar 3Feb 28Feb 23
16°FMar 13Mar 8Mar 6Mar 3Mar 1Feb 27Feb 23Feb 18Feb 11

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 25Sep 29Oct 2Oct 4Oct 7Oct 9Oct 12Oct 15Oct 19
32°FOct 3Oct 7Oct 11Oct 15Oct 17Oct 20Oct 22Oct 26Nov 1
28°FOct 14Oct 18Oct 20Oct 23Oct 26Oct 30Nov 1Nov 5Nov 10
24°FOct 20Oct 26Oct 30Nov 2Nov 6Nov 9Nov 12Nov 15Nov 21
20°FOct 30Nov 4Nov 8Nov 12Nov 15Nov 18Nov 22Nov 25Nov 30
16°FNov 6Nov 13Nov 16Nov 21Nov 24Nov 28Dec 1Dec 5Dec 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°F171165161156152148144138129
32°F194187182178175171166161154
28°F221214208203199195191185177
24°F249243235230225221215208200
20°F272264259255250245240233225
16°F291284278273268263258253244

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
6,008
Cooling degree days, base 65°F
916
Growing degree days, base 40°F
5,203
Growing degree days, base 45°F
4,034
Growing degree days, base 50°F
3,035
Growing degree days, base 55°F
2,191
Growing degree days, base 60°F
1,487

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,16200
February92100
March693018
April481174
May24623267
June68131514
July6364823
August5310770
September9485445
October4302118
November79206
December1,11000

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 0.2 km from Tremonton. 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 USC00428817 (Tremonton). Public domain.