Oshkosh climate

Oshkosh Frost Dates and Growing Season

NOAA 1991-2020 normals for Oshkosh, 1.3 km from Oshkosh, elevation 750 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Oshkosh. 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 24 and the first fall freeze around October 20, a growing season of about 178 days.

Median at 36°F
last May 4, first October 6
Median at 32°F
last April 24, first October 20
Median at 28°F
last April 13, first October 31

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 19May 13May 10May 8May 4May 2Apr 29Apr 25Apr 20
32°FMay 8May 3Apr 30Apr 28Apr 24Apr 21Apr 18Apr 15Apr 10
28°FApr 26Apr 21Apr 18Apr 15Apr 13Apr 10Apr 7Apr 4Mar 31
24°FApr 17Apr 12Apr 8Apr 6Apr 3Apr 2Mar 30Mar 25Mar 20
20°FApr 7Apr 4Apr 1Mar 30Mar 26Mar 23Mar 20Mar 17Mar 13
16°FApr 1Mar 28Mar 25Mar 22Mar 18Mar 16Mar 13Mar 10Mar 5

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 24Sep 28Oct 1Oct 4Oct 6Oct 9Oct 13Oct 16Oct 22
32°FOct 4Oct 9Oct 13Oct 17Oct 20Oct 23Oct 26Oct 30Nov 2
28°FOct 17Oct 22Oct 25Oct 29Oct 31Nov 2Nov 6Nov 9Nov 13
24°FOct 30Nov 1Nov 5Nov 8Nov 10Nov 13Nov 16Nov 20Nov 24
20°FNov 5Nov 9Nov 13Nov 16Nov 19Nov 21Nov 24Nov 27Dec 1
16°FNov 12Nov 17Nov 20Nov 23Nov 26Nov 28Dec 1Dec 5Dec 12

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°F175168163158155151147142136
32°F198191186182178174169164157
28°F219212208205200197193188181
24°F239232227223219216212208201
20°F256249244240236232227223217
16°F272264259254251246242238231

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
7,336
Cooling degree days, base 65°F
664
Growing degree days, base 40°F
4,664
Growing degree days, base 45°F
3,620
Growing degree days, base 50°F
2,699
Growing degree days, base 55°F
1,897
Growing degree days, base 60°F
1,216

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,45200
February1,22100
March1,011010
April600255
May26234263
June49140542
July8231688
August16184632
September13967385
October4746111
November854012
December1,25101

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 1.3 km from Oshkosh. 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 USC00476330 (Oshkosh). Public domain.