Willard climate

Willard Frost Dates and Growing Season

NOAA 1991-2020 normals for Brigham City Waste Plt, 12.8 km from Willard, elevation 4240 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brigham City Waste Plt. 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 5 and the first fall freeze around October 5, a growing season of about 150 days.

Median at 36°F
last May 23, first September 24
Median at 32°F
last May 5, first October 5
Median at 28°F
last April 18, first October 17

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 11Jun 6Jun 1May 28May 23May 19May 15May 11May 5
32°FMay 29May 19May 14May 9May 5May 2Apr 29Apr 26Apr 20
28°FMay 5Apr 30Apr 27Apr 23Apr 18Apr 15Apr 11Apr 6Mar 31
24°FApr 19Apr 12Apr 6Apr 2Mar 30Mar 25Mar 20Mar 14Mar 8
20°FMar 31Mar 24Mar 18Mar 12Mar 8Mar 5Mar 2Feb 27Feb 19
16°FMar 13Mar 8Mar 5Mar 1Feb 26Feb 22Feb 18Feb 12Feb 6

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 9Sep 15Sep 19Sep 22Sep 24Sep 28Oct 1Oct 3Oct 8
32°FSep 20Sep 26Sep 29Oct 2Oct 5Oct 7Oct 10Oct 15Oct 19
28°FOct 1Oct 6Oct 11Oct 15Oct 17Oct 21Oct 23Oct 27Nov 1
24°FOct 14Oct 20Oct 23Oct 27Oct 30Nov 2Nov 5Nov 9Nov 13
20°FOct 24Oct 30Nov 3Nov 7Nov 11Nov 14Nov 18Nov 22Nov 27
16°FNov 5Nov 10Nov 14Nov 19Nov 23Nov 26Nov 30Dec 3Dec 9

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°F14413713212712211811210699
32°F172165159155150146140133123
28°F205197191186181176170163155
24°F240231225219213208201196185
20°F269261255250244238233226216
16°F293285278274268262257252243

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
6,101
Cooling degree days, base 65°F
703
Growing degree days, base 40°F
4,918
Growing degree days, base 45°F
3,755
Growing degree days, base 50°F
2,761
Growing degree days, base 55°F
1,934
Growing degree days, base 60°F
1,249

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17000
February91101
March702013
April488168
May24817253
June68103486
July5291752
August8239696
September11852390
October455198
November80305
December1,12500

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 12.8 km from Willard. 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 USC00420928 (Brigham City Waste Plt). Public domain.