Bluffview climate

Bluffview Frost Dates and Growing Season

NOAA 1991-2020 normals for Baraboo, 10.4 km from Bluffview, elevation 823 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Baraboo. 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 18, first September 26
Median at 32°F
last May 5, first October 5
Median at 28°F
last April 24, 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°FJun 1May 28May 24May 21May 18May 14May 11May 8May 2
32°FMay 21May 16May 12May 8May 5May 2Apr 30Apr 26Apr 21
28°FMay 9May 3Apr 30Apr 28Apr 24Apr 22Apr 18Apr 15Apr 10
24°FApr 28Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1
20°FApr 18Apr 13Apr 9Apr 6Apr 4Apr 2Mar 31Mar 26Mar 20
16°FApr 9Apr 4Apr 1Mar 30Mar 26Mar 23Mar 19Mar 16Mar 12

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 11Sep 17Sep 20Sep 23Sep 26Sep 29Oct 1Oct 4Oct 7
32°FSep 22Sep 27Sep 30Oct 2Oct 5Oct 7Oct 11Oct 14Oct 19
28°FOct 1Oct 6Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27Nov 1
24°FOct 13Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 13
20°FOct 27Nov 1Nov 2Nov 5Nov 9Nov 12Nov 15Nov 19Nov 24
16°FNov 2Nov 8Nov 12Nov 15Nov 19Nov 22Nov 25Nov 28Dec 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°F150144140135131127122117110
32°F173165161156152148143138130
28°F195188183179174170166160154
24°F218211206201197193188182176
20°F239231226222218214210205199
16°F257251246241237233228224217

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
7,292
Cooling degree days, base 65°F
615
Growing degree days, base 40°F
4,606
Growing degree days, base 45°F
3,553
Growing degree days, base 50°F
2,625
Growing degree days, base 55°F
1,824
Growing degree days, base 60°F
1,148

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,44000
February1,19400
March975115
April584364
May25737272
June54131528
July13213665
August28160597
September16162360
October4908110
November854015
December1,24301

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 10.4 km from Bluffview. 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 USC00470516 (Baraboo). Public domain.