Wilson climate

Wilson Frost Dates and Growing Season

NOAA 1991-2020 normals for Wilson Lake, 15.8 km from Wilson, elevation 1512 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wilson Lake. 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 21 and the first fall freeze around October 17, a growing season of about 179 days.

Median at 36°F
last April 30, first October 9
Median at 32°F
last April 21, first October 17
Median at 28°F
last April 12, first October 26

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 11May 7May 4May 2Apr 30Apr 28Apr 25Apr 22Apr 17
32°FMay 2Apr 29Apr 26Apr 24Apr 21Apr 18Apr 16Apr 12Apr 7
28°FApr 26Apr 22Apr 19Apr 15Apr 12Apr 9Apr 5Apr 2Mar 28
24°FApr 19Apr 13Apr 9Apr 6Apr 3Mar 31Mar 28Mar 21Mar 14
20°FApr 11Apr 5Mar 31Mar 27Mar 22Mar 17Mar 13Mar 9Mar 3
16°FApr 1Mar 24Mar 18Mar 13Mar 10Mar 6Mar 2Feb 28Feb 22

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 24Sep 30Oct 3Oct 6Oct 9Oct 11Oct 14Oct 17Oct 21
32°FOct 3Oct 8Oct 13Oct 15Oct 17Oct 20Oct 22Oct 25Oct 29
28°FOct 13Oct 17Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 8
24°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 8Nov 11Nov 14Nov 20
20°FOct 30Nov 3Nov 8Nov 12Nov 16Nov 19Nov 24Nov 27Dec 1
16°FNov 7Nov 13Nov 18Nov 22Nov 26Nov 29Dec 2Dec 6Dec 14

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°F179172168165161157153148142
32°F199191186182179175171166159
28°F219212207202198194190185179
24°F240233227221217212207201194
20°F264256249243237232227220211
16°F286277270265260255249242231

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
5,137
Cooling degree days, base 65°F
1,473
Growing degree days, base 40°F
6,483
Growing degree days, base 45°F
5,207
Growing degree days, base 50°F
4,072
Growing degree days, base 55°F
3,073
Growing degree days, base 60°F
2,207

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07901
February879010
March657162
April37013174
May13293434
June12301739
July1460924
August3390852
September59183577
October30231249
November652148
December99203

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 15.8 km from Wilson. 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 USC00148946 (Wilson Lake). Public domain.