Shoshoni climate

Shoshoni Frost Dates and Growing Season

NOAA 1991-2020 normals for Shoshoni, 0.1 km from Shoshoni, elevation 4837 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Shoshoni. 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 7 and the first fall freeze around October 3, a growing season of about 145 days.

Median at 36°F
last May 19, first September 24
Median at 32°F
last May 7, first October 3
Median at 28°F
last April 28, first October 11

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 1May 28May 25May 22May 19May 17May 15May 11May 8
32°FMay 18May 15May 12May 9May 7May 5May 3Apr 30Apr 27
28°FMay 9May 5May 2Apr 30Apr 28Apr 25Apr 22Apr 19Apr 14
24°FApr 30Apr 26Apr 22Apr 18Apr 15Apr 12Apr 9Apr 5Mar 31
20°FApr 21Apr 16Apr 12Apr 7Apr 4Apr 1Mar 29Mar 24Mar 15
16°FApr 14Apr 7Apr 1Mar 29Mar 25Mar 20Mar 15Mar 11Mar 7

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 12Sep 17Sep 20Sep 22Sep 24Sep 26Sep 27Sep 30Oct 3
32°FSep 23Sep 26Sep 29Oct 1Oct 3Oct 5Oct 7Oct 11Oct 15
28°FSep 30Oct 3Oct 6Oct 9Oct 11Oct 14Oct 16Oct 20Oct 23
24°FOct 6Oct 11Oct 14Oct 17Oct 20Oct 23Oct 25Oct 28Nov 1
20°FOct 12Oct 17Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 9
16°FOct 18Oct 25Oct 29Nov 1Nov 4Nov 6Nov 10Nov 13Nov 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°F141135132128125122118114108
32°F161156152148145142139135129
28°F182177172168165162158153147
24°F205199193189185181177172164
20°F225219214208204200195189183
16°F245237231227222218212206197

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
7,670
Cooling degree days, base 65°F
641
Growing degree days, base 40°F
4,570
Growing degree days, base 45°F
3,506
Growing degree days, base 50°F
2,592
Growing degree days, base 55°F
1,818
Growing degree days, base 60°F
1,164

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,56300
February1,15300
March82508
April527055
May29312216
June6499485
July3278740
August13210662
September14841355
October576168
November1,01101
December1,49300

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 0.1 km from Shoshoni. 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 USC00488209 (Shoshoni). Public domain.