Sulligent climate

Sulligent Frost Dates and Growing Season

NOAA 1991-2020 normals for Vernon, 18.1 km from Sulligent, elevation 298 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Vernon. 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 March 29 and the first fall freeze around November 5, a growing season of about 222 days.

Median at 36°F
last April 10, first October 27
Median at 32°F
last March 29, first November 5
Median at 28°F
last March 13, first November 19

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°FApr 25Apr 20Apr 16Apr 13Apr 10Apr 7Apr 3Mar 29Mar 22
32°FApr 16Apr 10Apr 6Apr 2Mar 29Mar 25Mar 20Mar 14Mar 5
28°FApr 5Mar 29Mar 23Mar 17Mar 13Mar 8Mar 2Feb 25Feb 19
24°FMar 19Mar 11Mar 5Feb 28Feb 26Feb 20Feb 15Feb 7Jan 31
20°FMar 5Feb 28Feb 21Feb 14Feb 7Feb 1Jan 27Jan 19Jan 8
16°FFeb 26Feb 13Feb 5Jan 31Jan 26Jan 20Jan 15Jan 7Dec 29

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 14Oct 18Oct 22Oct 25Oct 27Oct 30Nov 2Nov 5Nov 11
32°FOct 22Oct 27Oct 31Nov 2Nov 5Nov 8Nov 12Nov 19Nov 27
28°FNov 1Nov 5Nov 10Nov 14Nov 19Nov 23Nov 28Dec 3Dec 9
24°FNov 10Nov 18Nov 24Nov 29Dec 3Dec 6Dec 12Dec 22Jan 1
20°FNov 25Dec 2Dec 8Dec 16Dec 24Dec 29Jan 2Jan 9Jan 19
16°FDec 6Dec 19Dec 27Jan 1Jan 4Jan 9Jan 15Jan 22Feb 2

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°F225216210205201196191186178
32°F252242233228222217211206197
28°F281270262255249243238231221
24°F317305297290283276270262250
20°F353339331323315307300291278
16°F365365363355346337331321306

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
96% of years
16°F or colder
71% 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
2,635
Cooling degree days, base 65°F
2,119
Growing degree days, base 40°F
8,771
Growing degree days, base 45°F
7,146
Growing degree days, base 50°F
5,656
Growing degree days, base 55°F
4,315
Growing degree days, base 60°F
3,131

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January646158
February475388
March30723234
April12865395
May25214654
June1398847
July0502967
August0491956
September9310751
October12093445
November35014179
December575380

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 18.1 km from Sulligent. 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 USC00018517 (Vernon). Public domain.