Slinger climate

Slinger Frost Dates and Growing Season

NOAA 1991-2020 normals for Slinger Wwtp, 1 km from Slinger, elevation 1029 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Slinger 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 5 and the first fall freeze around October 5, a growing season of about 152 days.

Median at 36°F
last May 17, first September 28
Median at 32°F
last May 5, first October 5
Median at 28°F
last April 25, first October 17

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 31May 27May 23May 20May 17May 14May 11May 7May 2
32°FMay 20May 15May 11May 8May 5May 2Apr 30Apr 26Apr 21
28°FMay 9May 4Apr 30Apr 28Apr 25Apr 22Apr 19Apr 16Apr 11
24°FApr 29Apr 24Apr 20Apr 16Apr 13Apr 11Apr 8Apr 5Apr 2
20°FApr 16Apr 11Apr 7Apr 5Apr 3Apr 2Mar 31Mar 26Mar 21
16°FApr 7Apr 3Apr 1Mar 30Mar 27Mar 23Mar 19Mar 16Mar 11

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 12Sep 18Sep 22Sep 24Sep 28Sep 30Oct 3Oct 5Oct 8
32°FSep 22Sep 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 15Oct 20
28°FOct 1Oct 6Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27Oct 31
24°FOct 14Oct 20Oct 24Oct 27Oct 29Nov 1Nov 4Nov 8Nov 13
20°FOct 28Nov 1Nov 4Nov 6Nov 10Nov 13Nov 15Nov 20Nov 25
16°FNov 4Nov 9Nov 12Nov 15Nov 19Nov 22Nov 24Nov 29Dec 4

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°F152144140136131127123119110
32°F170164160156152148144139133
28°F195188182177173170166160153
24°F217212208203199195190185177
20°F241234229224220216213208201
16°F259252247243238234229223216

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
7,884
Cooling degree days, base 65°F
411
Growing degree days, base 40°F
4,104
Growing degree days, base 45°F
3,111
Growing degree days, base 50°F
2,240
Growing degree days, base 55°F
1,490
Growing degree days, base 60°F
871

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49100
February1,25100
March1,066114
April659039
May33517200
June8379448
July26156595
August44112533
September19442314
October536386
November908011
December1,29300

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 km from Slinger. 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 USC00477796 (Slinger Wwtp). Public domain.