Hyndman climate

Hyndman Frost Dates and Growing Season

NOAA 1991-2020 normals for Cumberland 2, 20.4 km from Hyndman, elevation 730 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cumberland 2. 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 15 and the first fall freeze around October 24, a growing season of about 190 days.

Median at 36°F
last April 29, first October 13
Median at 32°F
last April 15, first October 24
Median at 28°F
last April 3, first November 3

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 18May 11May 7May 2Apr 29Apr 25Apr 21Apr 18Apr 13
32°FMay 5Apr 28Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2
28°FApr 17Apr 11Apr 8Apr 5Apr 3Apr 1Mar 30Mar 26Mar 20
24°FApr 5Apr 2Mar 30Mar 26Mar 23Mar 19Mar 17Mar 13Mar 7
20°FMar 25Mar 21Mar 17Mar 14Mar 11Mar 8Mar 4Feb 28Feb 22
16°FMar 17Mar 11Mar 7Mar 3Feb 28Feb 25Feb 19Feb 14Feb 7

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°FOct 1Oct 5Oct 8Oct 10Oct 13Oct 15Oct 18Oct 22Oct 26
32°FOct 9Oct 14Oct 18Oct 21Oct 24Oct 27Oct 30Nov 2Nov 6
28°FOct 20Oct 25Oct 28Nov 1Nov 3Nov 5Nov 9Nov 12Nov 19
24°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 22Nov 28Dec 4
20°FNov 11Nov 17Nov 22Nov 27Dec 1Dec 5Dec 9Dec 15Dec 22
16°FNov 27Dec 4Dec 9Dec 14Dec 19Dec 23Dec 26Jan 1Jan 8

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°F187180176172168163158152144
32°F210204200195190186182178169
28°F234227221217214210207202195
24°F264253247242237233228223217
20°F291282276270265260254248241
16°F316307301296291286281275265

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
5,119
Cooling degree days, base 65°F
1,042
Growing degree days, base 40°F
5,933
Growing degree days, base 45°F
4,675
Growing degree days, base 50°F
3,554
Growing degree days, base 55°F
2,574
Growing degree days, base 60°F
1,737

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05803
February87806
March711141
April35513175
May13671404
June17206639
July0333798
August3283746
September66118503
October32616196
November639038
December93005

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 20.4 km from Hyndman. 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 USC00182282 (Cumberland 2). Public domain.