Browns Lake climate

Browns Lake Frost Dates and Growing Season

NOAA 1991-2020 normals for Burlington, 5.1 km from Browns Lake, elevation 751 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Burlington. 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 9, a growing season of about 156 days.

Median at 36°F
last May 17, first September 30
Median at 32°F
last May 5, first October 9
Median at 28°F
last April 24, first October 22

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 28May 24May 20May 17May 13May 9May 6May 2
32°FMay 23May 16May 11May 8May 5May 2Apr 30Apr 26Apr 21
28°FMay 11May 4May 1Apr 28Apr 24Apr 21Apr 17Apr 14Apr 8
24°FApr 29Apr 23Apr 19Apr 15Apr 12Apr 8Apr 5Apr 2Mar 29
20°FApr 15Apr 9Apr 5Apr 3Apr 1Mar 30Mar 27Mar 22Mar 16
16°FApr 4Mar 31Mar 28Mar 25Mar 22Mar 19Mar 15Mar 12Mar 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 17Sep 22Sep 25Sep 28Sep 30Oct 2Oct 4Oct 8Oct 12
32°FSep 24Sep 30Oct 2Oct 6Oct 9Oct 12Oct 15Oct 19Oct 24
28°FOct 3Oct 10Oct 15Oct 18Oct 22Oct 24Oct 27Oct 30Nov 4
24°FOct 18Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 11Nov 15
20°FOct 31Nov 2Nov 5Nov 9Nov 12Nov 15Nov 19Nov 22Nov 27
16°FNov 7Nov 12Nov 15Nov 18Nov 21Nov 24Nov 28Dec 1Dec 6

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°F155148144139136132128123115
32°F177170165160156152147142134
28°F199192187182178174170164156
24°F225218213208204200195189181
20°F248241236232227223219213205
16°F267260255250245241236232225

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
7,369
Cooling degree days, base 65°F
500
Growing degree days, base 40°F
4,360
Growing degree days, base 45°F
3,324
Growing degree days, base 50°F
2,417
Growing degree days, base 55°F
1,641
Growing degree days, base 60°F
994

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,40700
February1,18400
March991012
April611250
May31326219
June78102475
July18177625
August27138577
September16349344
October4925103
November858012
December1,22801

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 5.1 km from Browns Lake. 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 USC00471205 (Burlington). Public domain.