Thorp climate

Thorp Frost Dates and Growing Season

NOAA 1991-2020 normals for Stanley Wwtp, 10 km from Thorp, elevation 1080 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stanley Wwtp. 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 147 days.

Median at 36°F
last May 18, first September 25
Median at 32°F
last May 7, first October 3
Median at 28°F
last April 26, first October 14

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 2May 28May 24May 21May 18May 15May 12May 8May 4
32°FMay 21May 16May 13May 10May 7May 4May 2Apr 29Apr 24
28°FMay 10May 5May 2Apr 30Apr 26Apr 24Apr 20Apr 16Apr 12
24°FApr 30Apr 25Apr 21Apr 18Apr 15Apr 12Apr 9Apr 5Apr 2
20°FApr 20Apr 15Apr 11Apr 8Apr 5Apr 3Apr 1Mar 29Mar 23
16°FApr 11Apr 6Apr 3Apr 1Mar 31Mar 27Mar 24Mar 20Mar 13

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 11Sep 17Sep 20Sep 23Sep 25Sep 27Sep 30Oct 3Oct 6
32°FSep 20Sep 25Sep 28Oct 1Oct 3Oct 5Oct 8Oct 12Oct 16
28°FSep 29Oct 3Oct 7Oct 11Oct 14Oct 17Oct 20Oct 24Oct 29
24°FOct 11Oct 16Oct 20Oct 24Oct 27Oct 29Nov 1Nov 4Nov 9
20°FOct 23Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 15Nov 20
16°FNov 1Nov 6Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Nov 30

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°F147140136132127124119115108
32°F168161156151147143139134127
28°F191183177173169165160155149
24°F213207202197193189184180172
20°F235227221217214210206201193
16°F251244239235231227222217211

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
8,298
Cooling degree days, base 65°F
442
Growing degree days, base 40°F
4,117
Growing degree days, base 45°F
3,139
Growing degree days, base 50°F
2,274
Growing degree days, base 55°F
1,525
Growing degree days, base 60°F
908

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,61800
February1,34400
March1,09605
April651146
May30020225
June7796470
July23164606
August39119546
September20739299
October576473
November96505
December1,40400

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 10 km from Thorp. 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 USC00478110 (Stanley Wwtp). Public domain.