Shokan climate

Shokan Frost Dates and Growing Season

NOAA 1991-2020 normals for Slide Mtn, 17.6 km from Shokan, elevation 2650 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Slide Mtn. 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 6 and the first fall freeze around October 7, a growing season of about 154 days.

Median at 36°F
last May 21, first September 27
Median at 32°F
last May 6, first October 7
Median at 28°F
last April 26, first October 21

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 4May 31May 28May 24May 21May 18May 14May 10May 5
32°FMay 23May 17May 12May 8May 6May 3Apr 30Apr 28Apr 25
28°FMay 8May 3Apr 30Apr 28Apr 26Apr 24Apr 22Apr 19Apr 15
24°FApr 26Apr 23Apr 20Apr 17Apr 15Apr 12Apr 9Apr 6Apr 3
20°FApr 18Apr 15Apr 11Apr 8Apr 6Apr 4Apr 2Apr 1Mar 27
16°FApr 11Apr 6Apr 4Apr 2Apr 1Mar 29Mar 26Mar 22Mar 17

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 14Sep 19Sep 23Sep 25Sep 27Sep 30Oct 2Oct 5Oct 10
32°FSep 26Oct 1Oct 2Oct 4Oct 7Oct 10Oct 14Oct 17Oct 24
28°FOct 5Oct 10Oct 15Oct 18Oct 21Oct 25Oct 28Nov 1Nov 5
24°FOct 18Oct 24Oct 28Oct 31Nov 2Nov 4Nov 7Nov 10Nov 15
20°FNov 1Nov 5Nov 7Nov 10Nov 13Nov 15Nov 18Nov 23Nov 29
16°FNov 10Nov 14Nov 17Nov 21Nov 24Nov 27Dec 1Dec 4Dec 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°F148141136131128124120115110
32°F174166161157154150146140134
28°F197190186182178173169164157
24°F219213208205202198195190183
20°F241233229225221217213209204
16°F259251246242238234231227221

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
8,090
Cooling degree days, base 65°F
149
Growing degree days, base 40°F
3,483
Growing degree days, base 45°F
2,504
Growing degree days, base 50°F
1,671
Growing degree days, base 55°F
983
Growing degree days, base 60°F
463

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,39801
February1,21200
March1,11603
April726130
May3928147
June16626316
July6659459
August9143417
September24711233
October579159
November88207
December1,21701

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 17.6 km from Shokan. 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 USC00307799 (Slide Mtn). Public domain.