Lawson climate

Lawson Frost Dates and Growing Season

NOAA 1991-2020 normals for Kearney 3E, 13.4 km from Lawson, elevation 840 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kearney 3E. 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 19 and the first fall freeze around October 17, a growing season of about 181 days.

Median at 36°F
last April 29, first October 8
Median at 32°F
last April 19, first October 17
Median at 28°F
last April 8, first October 27

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 12May 7May 4May 1Apr 29Apr 26Apr 23Apr 19Apr 14
32°FMay 5Apr 30Apr 26Apr 23Apr 19Apr 15Apr 12Apr 9Apr 4
28°FApr 24Apr 20Apr 15Apr 12Apr 8Apr 5Apr 2Mar 29Mar 22
24°FApr 14Apr 8Apr 4Apr 1Mar 29Mar 25Mar 20Mar 16Mar 10
20°FApr 3Mar 29Mar 24Mar 19Mar 16Mar 13Mar 9Mar 5Feb 28
16°FMar 26Mar 19Mar 15Mar 11Mar 7Mar 4Mar 2Feb 26Feb 20

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

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°F179173169164160157152148142
32°F201194189185181177172166159
28°F222214209205201198194188181
24°F247237231225220217213207199
20°F268258253247242237232225217
16°F285278273267262258252247240

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
5,342
Cooling degree days, base 65°F
1,266
Growing degree days, base 40°F
6,209
Growing degree days, base 45°F
4,954
Growing degree days, base 50°F
3,832
Growing degree days, base 55°F
2,846
Growing degree days, base 60°F
1,991

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15802
February92307
March684459
April35815180
May12992432
June11264703
July1387851
August2338801
September68141525
October32125223
November664146
December1,02404

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 13.4 km from Lawson. 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 USC00234382 (Kearney 3E). Public domain.