Franklin climate

Franklin Frost Dates and Growing Season

NOAA 1991-2020 normals for Hales Corners/whitnall Park/bo, 5.4 km from Franklin, elevation 774 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hales Corners/whitnall Park/bo. 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 3 and the first fall freeze around October 14, a growing season of about 162 days.

Median at 36°F
last May 14, first October 3
Median at 32°F
last May 3, first October 14
Median at 28°F
last April 21, first October 24

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 29May 25May 20May 17May 14May 11May 7May 4Apr 30
32°FMay 19May 13May 9May 5May 3Apr 30Apr 27Apr 23Apr 18
28°FMay 9May 2Apr 29Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8
24°FApr 25Apr 18Apr 15Apr 11Apr 9Apr 6Apr 4Apr 1Mar 27
20°FApr 11Apr 7Apr 3Apr 1Mar 30Mar 27Mar 24Mar 20Mar 15
16°FApr 2Mar 29Mar 26Mar 23Mar 20Mar 17Mar 14Mar 11Mar 6

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 22Sep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 11Oct 15
32°FSep 30Oct 5Oct 8Oct 11Oct 14Oct 16Oct 19Oct 22Oct 26
28°FOct 8Oct 14Oct 19Oct 22Oct 24Oct 27Oct 30Nov 1Nov 6
24°FOct 23Oct 28Oct 31Nov 2Nov 4Nov 7Nov 10Nov 13Nov 18
20°FNov 2Nov 6Nov 9Nov 12Nov 15Nov 17Nov 20Nov 24Nov 28
16°FNov 9Nov 14Nov 18Nov 21Nov 24Nov 27Dec 1Dec 5Dec 11

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°F161155150145141137132128122
32°F181174170165162158154149142
28°F204196192188183179175169163
24°F226219215211207203199193186
20°F251244238234229225222217211
16°F269262257253249244240235228

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
7,037
Cooling degree days, base 65°F
608
Growing degree days, base 40°F
4,631
Growing degree days, base 45°F
3,568
Growing degree days, base 50°F
2,635
Growing degree days, base 55°F
1,832
Growing degree days, base 60°F
1,153

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,36400
February1,14901
March962112
April594254
May28430244
June62116505
July9215671
August15174625
September13264387
October4537123
November825013
December1,18901

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 5.4 km from Franklin. 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 USC00473391 (Hales Corners/whitnall Park/bo). Public domain.