Bountiful climate

Bountiful Frost Dates and Growing Season

NOAA 1991-2020 normals for Bountiful Bench, 2.6 km from Bountiful, elevation 4950 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bountiful Bench. 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 25 and the first fall freeze around October 24, a growing season of about 181 days.

Median at 36°F
last May 8, first October 14
Median at 32°F
last April 25, first October 24
Median at 28°F
last April 5, first November 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°FMay 31May 23May 17May 12May 8May 4May 1Apr 28Apr 23
32°FMay 14May 6May 1Apr 28Apr 25Apr 21Apr 17Apr 11Apr 5
28°FApr 28Apr 20Apr 15Apr 9Apr 5Apr 1Mar 28Mar 19Mar 12
24°FApr 6Mar 31Mar 24Mar 18Mar 13Mar 10Mar 7Mar 2Feb 23
20°FMar 17Mar 11Mar 7Mar 3Feb 28Feb 24Feb 20Feb 16Feb 7
16°FMar 5Feb 28Feb 23Feb 19Feb 15Feb 10Feb 6Feb 1Jan 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 30Oct 4Oct 7Oct 11Oct 14Oct 17Oct 19Oct 23Oct 27
32°FOct 9Oct 15Oct 18Oct 21Oct 24Oct 27Oct 30Nov 2Nov 7
28°FOct 20Oct 25Oct 29Nov 1Nov 4Nov 7Nov 9Nov 13Nov 18
24°FOct 29Nov 4Nov 7Nov 11Nov 14Nov 17Nov 21Nov 24Nov 29
20°FNov 7Nov 13Nov 16Nov 20Nov 23Nov 26Nov 29Dec 4Dec 10
16°FNov 14Nov 20Nov 24Nov 28Dec 1Dec 5Dec 10Dec 16Dec 21

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°F177170165161156152146140130
32°F203196189185181176171166158
28°F234227221215209204199191181
24°F266257251245239234227221211
20°F294285277273268262256250240
16°F320309303296290284278272262

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
5,937
Cooling degree days, base 65°F
928
Growing degree days, base 40°F
5,217
Growing degree days, base 45°F
4,054
Growing degree days, base 50°F
3,057
Growing degree days, base 55°F
2,214
Growing degree days, base 60°F
1,510

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10400
February87102
March704023
April511378
May26130264
June72145526
July4359820
August7298756
September10388442
October4305131
November783015
December1,08801

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 2.6 km from Bountiful. 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 USC00420819 (Bountiful Bench). Public domain.