Laurium climate

Laurium Frost Dates and Growing Season

NOAA 1991-2020 normals for Hancock Houghton CO AP, 8.4 km from Laurium, elevation 1063 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hancock Houghton CO AP. 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 17 and the first fall freeze around October 1, a growing season of about 138 days.

Median at 36°F
last June 1, first September 21
Median at 32°F
last May 17, first October 1
Median at 28°F
last May 2, 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 13Jun 8Jun 5Jun 3Jun 1May 29May 25May 22May 16
32°FJun 3May 30May 24May 21May 17May 13May 9May 5May 1
28°FMay 20May 15May 10May 6May 2Apr 30Apr 28Apr 24Apr 19
24°FMay 6Apr 30Apr 28Apr 25Apr 22Apr 20Apr 16Apr 13Apr 8
20°FApr 25Apr 21Apr 18Apr 15Apr 12Apr 9Apr 6Apr 3Mar 31
16°FApr 19Apr 14Apr 11Apr 7Apr 5Apr 3Apr 1Mar 29Mar 23

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 3Sep 10Sep 14Sep 18Sep 21Sep 24Sep 27Oct 1Oct 5
32°FSep 16Sep 22Sep 26Sep 29Oct 1Oct 4Oct 8Oct 11Oct 18
28°FSep 28Oct 3Oct 7Oct 11Oct 14Oct 17Oct 21Oct 26Nov 1
24°FOct 13Oct 18Oct 23Oct 27Oct 30Nov 2Nov 5Nov 9Nov 14
20°FOct 28Nov 1Nov 5Nov 8Nov 11Nov 14Nov 16Nov 20Nov 25
16°FNov 4Nov 11Nov 14Nov 17Nov 20Nov 23Nov 26Dec 1Dec 5

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°F1331261211171131081039890
32°F159152147143138134129124116
28°F185178173169164159154148141
24°F211203198194190186181176166
20°F231224219215212208203198192
16°F247240235231227223220216209

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
9,013
Cooling degree days, base 65°F
206
Growing degree days, base 40°F
3,227
Growing degree days, base 45°F
2,353
Growing degree days, base 50°F
1,605
Growing degree days, base 55°F
984
Growing degree days, base 60°F
508

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,51600
February1,34500
March1,23402
April836013
May4698114
June19132300
July7980467
August9164439
September27721225
October652144
November99003
December1,33500

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 8.4 km from Laurium. 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 USW00014858 (Hancock Houghton CO AP). Public domain.