Wrightstown climate

Wrightstown Frost Dates and Growing Season

NOAA 1991-2020 normals for Brillion, 19.5 km from Wrightstown, elevation 810 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brillion. 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 6, a growing season of about 151 days.

Median at 36°F
last May 17, first September 26
Median at 32°F
last May 6, first October 6
Median at 28°F
last April 25, first October 18

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 30May 26May 23May 20May 17May 14May 11May 7May 3
32°FMay 21May 16May 12May 8May 6May 3Apr 30Apr 27Apr 22
28°FMay 12May 6May 1Apr 29Apr 25Apr 22Apr 19Apr 15Apr 9
24°FApr 28Apr 22Apr 19Apr 16Apr 13Apr 9Apr 6Apr 3Mar 30
20°FApr 15Apr 9Apr 5Apr 3Apr 1Mar 30Mar 26Mar 22Mar 17
16°FApr 5Apr 1Mar 30Mar 27Mar 24Mar 20Mar 18Mar 15Mar 10

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 18Sep 21Sep 24Sep 26Sep 29Oct 1Oct 4Oct 8
32°FSep 23Sep 28Oct 1Oct 3Oct 6Oct 8Oct 12Oct 15Oct 21
28°FOct 2Oct 8Oct 11Oct 15Oct 18Oct 22Oct 25Oct 31Nov 4
24°FOct 15Oct 21Oct 26Oct 30Nov 1Nov 4Nov 6Nov 10Nov 15
20°FOct 30Nov 2Nov 5Nov 9Nov 13Nov 16Nov 19Nov 23Nov 28
16°FNov 5Nov 11Nov 16Nov 19Nov 23Nov 25Nov 29Dec 2Dec 8

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°F150143138134130127123119112
32°F173165160156151147143138131
28°F198189184180175170165160152
24°F222215209205201197192185177
20°F247239234229225221216210204
16°F263257251247243238234229222

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
7,667
Cooling degree days, base 65°F
491
Growing degree days, base 40°F
4,266
Growing degree days, base 45°F
3,257
Growing degree days, base 50°F
2,374
Growing degree days, base 55°F
1,614
Growing degree days, base 60°F
976

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,46600
February1,23900
March1,04509
April643144
May29824227
June69110491
July20186631
August36121550
September18045327
October527587
November88108
December1,26300

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 19.5 km from Wrightstown. 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 USC00471064 (Brillion). Public domain.