Burt climate

Burt Frost Dates and Growing Season

NOAA 1991-2020 normals for Algona, 14.6 km from Burt, elevation 1214 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Algona. 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 30 and the first fall freeze around October 6, a growing season of about 160 days.

Median at 36°F
last May 9, first September 28
Median at 32°F
last April 30, first October 6
Median at 28°F
last April 20, first October 18

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 20May 16May 13May 11May 9May 6May 4May 1Apr 28
32°FMay 11May 7May 4May 2Apr 30Apr 28Apr 24Apr 21Apr 16
28°FMay 2Apr 29Apr 25Apr 22Apr 20Apr 17Apr 14Apr 9Apr 4
24°FApr 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Apr 1Mar 25
20°FApr 16Apr 10Apr 7Apr 4Apr 1Mar 30Mar 26Mar 21Mar 15
16°FApr 9Apr 4Apr 1Mar 28Mar 24Mar 20Mar 17Mar 13Mar 7

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 16Sep 20Sep 23Sep 26Sep 28Oct 1Oct 3Oct 6Oct 10
32°FSep 23Sep 28Oct 1Oct 4Oct 6Oct 9Oct 12Oct 16Oct 20
28°FOct 2Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 27Nov 1
24°FOct 13Oct 19Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 10
20°FOct 23Oct 28Nov 1Nov 2Nov 5Nov 7Nov 10Nov 13Nov 18
16°FNov 1Nov 3Nov 6Nov 9Nov 12Nov 14Nov 18Nov 21Nov 26

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°F160153148145142138134130125
32°F179172167163160156152147141
28°F200193189184180176172166159
24°F218211206203199195191185178
20°F237229224220216212208203195
16°F253246241236231227223218210

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
7,568
Cooling degree days, base 65°F
670
Growing degree days, base 40°F
4,732
Growing degree days, base 45°F
3,690
Growing degree days, base 50°F
2,756
Growing degree days, base 55°F
1,937
Growing degree days, base 60°F
1,238

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,53600
February1,26700
March1,003011
April570369
May24139287
June37157570
July8229687
August19165611
September13968388
October4848122
November921011
December1,34400

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 14.6 km from Burt. 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 USC00130133 (Algona). Public domain.