Laurel climate

Laurel Frost Dates and Growing Season

NOAA 1991-2020 normals for Billings WFO, 18.1 km from Laurel, elevation 3185 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Billings WFO. 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 3, a growing season of about 149 days.

Median at 36°F
last May 19, first September 23
Median at 32°F
last May 5, first October 3
Median at 28°F
last April 23, first October 14

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

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 9Sep 14Sep 18Sep 21Sep 23Sep 26Sep 29Oct 1Oct 5
32°FSep 20Sep 24Sep 28Oct 1Oct 3Oct 5Oct 9Oct 12Oct 17
28°FSep 29Oct 3Oct 8Oct 11Oct 14Oct 16Oct 20Oct 23Oct 27
24°FOct 10Oct 15Oct 18Oct 21Oct 25Oct 27Oct 30Nov 2Nov 6
20°FOct 17Oct 23Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 16
16°FOct 26Oct 30Nov 2Nov 6Nov 9Nov 11Nov 14Nov 18Nov 24

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°F144138134129125122118114107
32°F169161157153149146141137130
28°F193187181176172168163158151
24°F218211206201196193187182174
20°F239231225221217212208202193
16°F256249243238233229224219210

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
6,766
Cooling degree days, base 65°F
606
Growing degree days, base 40°F
4,588
Growing degree days, base 45°F
3,477
Growing degree days, base 50°F
2,534
Growing degree days, base 55°F
1,748
Growing degree days, base 60°F
1,108

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,20400
February1,00002
March831012
April557052
May29715217
June7783457
July7250708
August22209653
September17246339
October533385
November89009
December1,17800

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 18.1 km from Laurel. 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 USC00240801 (Billings WFO). Public domain.