Friendship climate

Friendship Frost Dates and Growing Season

NOAA 1991-2020 normals for Friendship, 1.2 km from Friendship, elevation 945 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Friendship. 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 9 and the first fall freeze around October 3, a growing season of about 147 days.

Median at 36°F
last May 20, first September 24
Median at 32°F
last May 9, first October 3
Median at 28°F
last April 29, first October 13

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 28May 25May 22May 20May 17May 14May 10May 4
32°FMay 23May 19May 15May 12May 9May 5May 2Apr 28Apr 23
28°FMay 14May 9May 4May 1Apr 29Apr 26Apr 22Apr 19Apr 14
24°FMay 4Apr 29Apr 25Apr 21Apr 18Apr 14Apr 11Apr 7Apr 3
20°FApr 24Apr 17Apr 12Apr 9Apr 6Apr 4Apr 1Mar 30Mar 22
16°FApr 12Apr 7Apr 3Apr 1Mar 30Mar 25Mar 22Mar 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 10Sep 15Sep 19Sep 21Sep 24Sep 26Sep 29Oct 3Oct 6
32°FSep 19Sep 24Sep 27Sep 30Oct 3Oct 5Oct 8Oct 11Oct 16
28°FSep 27Oct 3Oct 7Oct 10Oct 13Oct 16Oct 18Oct 22Oct 27
24°FOct 9Oct 16Oct 20Oct 22Oct 25Oct 27Oct 30Nov 2Nov 7
20°FOct 23Oct 28Oct 31Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19
16°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Nov 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°F147140134130127123119113106
32°F166160155151147143138133127
28°F186180174170166162157153146
24°F208202197192188184179174166
20°F232224218214210205201196189
16°F252243239234231226222217210

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
7,811
Cooling degree days, base 65°F
547
Growing degree days, base 40°F
4,374
Growing degree days, base 45°F
3,364
Growing degree days, base 50°F
2,476
Growing degree days, base 55°F
1,704
Growing degree days, base 60°F
1,055

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,52800
February1,27300
March1,041113
April626253
May28029247
June55118513
July17195643
August30146581
September18551331
October543585
November91409
December1,32100

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 1.2 km from Friendship. 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 USC00472973 (Friendship). Public domain.