Amery climate

Amery Frost Dates and Growing Season

NOAA 1991-2020 normals for Amery, 0.7 km from Amery, elevation 1070 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Amery. 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 4, a growing season of about 151 days.

Median at 36°F
last May 16, first September 27
Median at 32°F
last May 5, first October 4
Median at 28°F
last April 25, first October 15

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

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

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°F152145140136131128124119112
32°F171164160155151147143138130
28°F193186181176172168163158151
24°F215208203199195191186180174
20°F234227222218214210205199193
16°F252244239234230226222217210

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
8,288
Cooling degree days, base 65°F
489
Growing degree days, base 40°F
4,211
Growing degree days, base 45°F
3,229
Growing degree days, base 50°F
2,359
Growing degree days, base 55°F
1,606
Growing degree days, base 60°F
974

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,62100
February1,34000
March1,09106
April649147
May29224232
June7097478
July16184632
August33134566
September19246322
October581370
November98406
December1,41800

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 0.7 km from Amery. 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 USC00470175 (Amery). Public domain.