Parma climate

Parma Frost Dates and Growing Season

NOAA 1991-2020 normals for Parma Exp Stn, 1.9 km from Parma, elevation 2290 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Parma Exp Stn. 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 27 and the first fall freeze around October 9, a growing season of about 165 days.

Median at 36°F
last May 8, first September 28
Median at 32°F
last April 27, first October 9
Median at 28°F
last April 12, first October 22

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 27May 19May 15May 11May 8May 5May 3Apr 30Apr 27
32°FMay 9May 4May 1Apr 29Apr 27Apr 24Apr 21Apr 18Apr 13
28°FApr 28Apr 23Apr 19Apr 16Apr 12Apr 8Apr 5Apr 1Mar 27
24°FApr 12Apr 6Apr 2Mar 30Mar 25Mar 20Mar 15Mar 9Mar 2
20°FMar 29Mar 16Mar 11Mar 5Mar 1Feb 27Feb 21Feb 15Feb 7
16°FMar 6Feb 28Feb 24Feb 19Feb 14Feb 8Feb 2Jan 26Jan 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 19Sep 23Sep 26Sep 28Oct 1Oct 3Oct 6Oct 11
32°FSep 26Oct 1Oct 4Oct 6Oct 9Oct 12Oct 16Oct 19Oct 26
28°FOct 6Oct 11Oct 15Oct 19Oct 22Oct 25Oct 28Nov 1Nov 5
24°FOct 18Oct 23Oct 27Oct 31Nov 2Nov 6Nov 10Nov 14Nov 21
20°FOct 29Nov 2Nov 7Nov 11Nov 15Nov 20Nov 24Nov 28Dec 3
16°FNov 6Nov 12Nov 19Nov 24Nov 29Dec 1Dec 6Dec 12Dec 21

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°F159153149145141136132126116
32°F185178173170165161158153146
28°F214205200197192188183177170
24°F250242233228222218212206197
20°F287279271264259253247240231
16°F325313303297290283277269257

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
5,691
Cooling degree days, base 65°F
789
Growing degree days, base 40°F
5,141
Growing degree days, base 45°F
3,936
Growing degree days, base 50°F
2,912
Growing degree days, base 55°F
2,055
Growing degree days, base 60°F
1,350

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08300
February81601
March648018
April443287
May20636304
June67113497
July7307765
August14260711
September10469418
October4362107
November79605
December1,07100

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 1.9 km from Parma. 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 USC00106844 (Parma Exp Stn). Public domain.