Forman climate

Forman Frost Dates and Growing Season

NOAA 1991-2020 normals for Forman 5 Sse, 8.9 km from Forman, elevation 1250 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Forman 5 Sse. 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 7 and the first fall freeze around October 1, a growing season of about 146 days.

Median at 36°F
last May 17, first September 22
Median at 32°F
last May 7, first October 1
Median at 28°F
last April 29, first October 9

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 30May 26May 23May 20May 17May 14May 11May 8May 4
32°FMay 20May 16May 12May 9May 7May 4May 1Apr 29Apr 24
28°FMay 12May 7May 3May 1Apr 29Apr 26Apr 23Apr 19Apr 15
24°FMay 2Apr 28Apr 24Apr 21Apr 18Apr 16Apr 12Apr 9Apr 5
20°FApr 23Apr 18Apr 15Apr 11Apr 9Apr 7Apr 4Apr 2Mar 29
16°FApr 15Apr 10Apr 7Apr 4Apr 2Mar 31Mar 28Mar 23Mar 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 10Sep 14Sep 17Sep 20Sep 22Sep 25Sep 27Sep 29Oct 3
32°FSep 18Sep 23Sep 26Sep 28Oct 1Oct 2Oct 5Oct 9Oct 13
28°FSep 27Oct 1Oct 3Oct 6Oct 9Oct 12Oct 15Oct 19Oct 23
24°FOct 4Oct 9Oct 13Oct 17Oct 20Oct 23Oct 25Oct 29Nov 2
20°FOct 13Oct 20Oct 23Oct 26Oct 30Nov 1Nov 3Nov 7Nov 12
16°FOct 24Oct 29Nov 1Nov 4Nov 6Nov 9Nov 12Nov 16Nov 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°F146139135131127124121116110
32°F166159155150146143139135128
28°F183177172168164160156151145
24°F203197192187182179175169163
20°F221214209205201196191187180
16°F238231226221217213209204196

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
8,993
Cooling degree days, base 65°F
466
Growing degree days, base 40°F
4,041
Growing degree days, base 45°F
3,099
Growing degree days, base 50°F
2,264
Growing degree days, base 55°F
1,539
Growing degree days, base 60°F
934

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,74100
February1,44800
March1,19403
April696037
May32520215
June7891465
July19179625
August38134561
September21740294
October635363
November1,08002
December1,52400

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 8.9 km from Forman. 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 USC00323117 (Forman 5 Sse). Public domain.