Garrett County climate

Garrett County Frost Dates and Growing Season

NOAA 1991-2020 normals for Savage Rvr Dam, 11.7 km from Garrett County, elevation 1495 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Savage Rvr Dam. 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 29 and the first fall freeze around October 20, a growing season of about 174 days.

Median at 36°F
last May 8, first October 6
Median at 32°F
last April 29, first October 20
Median at 28°F
last April 12, first November 1

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

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 22Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 16Oct 21
32°FOct 4Oct 9Oct 13Oct 16Oct 20Oct 24Oct 26Oct 30Nov 2
28°FOct 16Oct 22Oct 26Oct 29Nov 1Nov 3Nov 6Nov 10Nov 15
24°FOct 29Nov 2Nov 6Nov 9Nov 12Nov 15Nov 19Nov 23Nov 30
20°FNov 7Nov 12Nov 17Nov 20Nov 24Nov 28Dec 2Dec 7Dec 15
16°FNov 17Nov 23Nov 30Dec 4Dec 8Dec 15Dec 20Dec 25Jan 1

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°F172164159154150146142136130
32°F196188183179174170165160151
28°F223216211207203198194189179
24°F251242236231226222217212206
20°F278269262257251246240235228
16°F301293286281275270264258250

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
6,026
Cooling degree days, base 65°F
512
Growing degree days, base 40°F
4,828
Growing degree days, base 45°F
3,660
Growing degree days, base 50°F
2,642
Growing degree days, base 55°F
1,778
Growing degree days, base 60°F
1,063

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14201
February97202
March840017
April480396
May23424273
June5597492
July10183639
August18148595
September12152384
October4285120
November722020
December1,00603

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 11.7 km from Garrett County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00188065 (Savage Rvr Dam). Public domain.