Glenmore climate

Glenmore Frost Dates and Growing Season

NOAA 1991-2020 normals for Denmark Wwtp, 9.9 km from Glenmore, elevation 811 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Denmark Wwtp. 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 6 and the first fall freeze around October 12, a growing season of about 158 days.

Median at 36°F
last May 18, first October 1
Median at 32°F
last May 6, first October 12
Median at 28°F
last April 23, first October 26

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 1May 27May 24May 21May 18May 15May 12May 8May 4
32°FMay 20May 15May 11May 8May 6May 2Apr 30Apr 27Apr 22
28°FMay 9May 3Apr 30Apr 27Apr 23Apr 21Apr 18Apr 14Apr 9
24°FApr 24Apr 19Apr 17Apr 14Apr 11Apr 8Apr 5Apr 3Mar 29
20°FApr 16Apr 11Apr 7Apr 4Apr 2Mar 31Mar 28Mar 24Mar 18
16°FApr 7Apr 2Mar 31Mar 28Mar 25Mar 22Mar 19Mar 15Mar 11

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 19Sep 23Sep 26Sep 29Oct 1Oct 3Oct 6Oct 9Oct 14
32°FSep 30Oct 3Oct 6Oct 9Oct 12Oct 15Oct 18Oct 22Oct 27
28°FOct 11Oct 16Oct 19Oct 23Oct 26Oct 29Nov 1Nov 4Nov 9
24°FOct 26Oct 30Nov 1Nov 3Nov 5Nov 9Nov 12Nov 15Nov 20
20°FNov 3Nov 8Nov 11Nov 14Nov 17Nov 19Nov 22Nov 25Nov 30
16°FNov 10Nov 15Nov 19Nov 22Nov 24Nov 27Nov 30Dec 3Dec 8

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°F154148144140136133129124118
32°F179172166162158155151146139
28°F203196191187183179175170163
24°F228221216212208205201196190
20°F248241236232228225220214208
16°F264257253249244240237232225

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
7,789
Cooling degree days, base 65°F
417
Growing degree days, base 40°F
4,128
Growing degree days, base 45°F
3,130
Growing degree days, base 50°F
2,259
Growing degree days, base 55°F
1,510
Growing degree days, base 60°F
885

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,47200
February1,25400
March1,07007
April672029
May32315201
June8273442
July21158603
August32125558
September17244331
October523282
November89107
December1,27700

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 9.9 km from Glenmore. 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 USC00472055 (Denmark Wwtp). Public domain.