Fox River climate

Fox River Frost Dates and Growing Season

NOAA 1991-2020 normals for Homer 9 E, 25.9 km from Fox River, elevation 512 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Homer 9 E. 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 27 and the first fall freeze around September 22, a growing season of about 116 days.

Median at 32°F
last May 27, first September 22
Median at 28°F
last May 9, first October 4

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°F–––––––––
32°FJun 8Jun 3Jun 1May 30May 27May 25May 22May 19May 14
28°FMay 22May 18May 15May 12May 9May 6May 3Apr 30Apr 25
24°FMay 6May 1Apr 27Apr 24Apr 20Apr 16Apr 12Apr 9Apr 5
20°FApr 24Apr 18Apr 13Apr 10Apr 7Apr 4Apr 2Mar 31Mar 25
16°FApr 15Apr 10Apr 6Apr 4Apr 2Mar 31Mar 28Mar 24Mar 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°F–––––––––
32°FSep 4Sep 10Sep 14Sep 18Sep 22Sep 25Sep 27Sep 30Oct 5
28°FSep 19Sep 25Sep 29Oct 1Oct 4Oct 7Oct 11Oct 16Oct 22
24°FOct 1Oct 5Oct 9Oct 13Oct 16Oct 19Oct 23Oct 28Nov 2
20°FOct 10Oct 17Oct 20Oct 24Oct 27Oct 30Nov 2Nov 6Nov 12
16°FOct 21Oct 25Oct 29Nov 1Nov 5Nov 8Nov 12Nov 17Nov 24

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°F999287827874696354
32°F13412712211911611210710296
28°F168161155151147143139134125
24°F199192187182178173169164156
20°F222214208204200195191186178
16°F239231226221217212208202195

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
9,755
Cooling degree days, base 65°F
0
Growing degree days, base 40°F
1,704
Growing degree days, base 45°F
938
Growing degree days, base 50°F
379
Growing degree days, base 55°F
77
Growing degree days, base 60°F
6

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29300
February1,08200
March1,14900
April83100
May63108
June419063
July3150152
August3400131
September522023
October83102
November1,09100
December1,25400

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 25.9 km from Fox River. 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 USC00503682 (Homer 9 E). Public domain.