Nelsonia climate

Nelsonia Frost Dates and Growing Season

NOAA 1991-2020 normals for Wallops Island Flight Fac, 17.3 km from Nelsonia, elevation 38 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wallops Island Flight Fac. 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 31 and the first fall freeze around November 11, a growing season of about 225 days.

Median at 36°F
last April 13, first October 31
Median at 32°F
last March 31, first November 11
Median at 28°F
last March 20, first November 24

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 1Apr 24Apr 19Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31
32°FApr 13Apr 9Apr 6Apr 3Mar 31Mar 29Mar 26Mar 22Mar 17
28°FApr 2Mar 30Mar 27Mar 23Mar 20Mar 17Mar 13Mar 8Mar 2
24°FMar 23Mar 18Mar 14Mar 11Mar 7Mar 4Feb 28Feb 23Feb 16
20°FMar 15Mar 6Mar 2Feb 27Feb 22Feb 16Feb 11Feb 5Jan 29
16°FFeb 28Feb 21Feb 13Feb 7Feb 3Jan 30Jan 24Jan 18Jan 10

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 16Oct 22Oct 26Oct 28Oct 31Nov 1Nov 4Nov 7Nov 12
32°FOct 31Nov 2Nov 5Nov 8Nov 11Nov 13Nov 17Nov 20Nov 26
28°FNov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 1Dec 5Dec 11
24°FNov 17Nov 25Nov 30Dec 4Dec 8Dec 12Dec 19Dec 24Dec 30
20°FDec 3Dec 9Dec 16Dec 23Dec 28Jan 1Jan 5Jan 10Jan 17
16°FDec 17Dec 26Jan 1Jan 5Jan 9Jan 13Jan 17Jan 23Feb 1

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°F221213209205201197193188180
32°F246238233229225220217212205
28°F274266261255250245241236227
24°F303294288282277271266260252
20°F334324317310306301295288278
16°F365353343336332326320312305

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
99% of years
16°F or colder
90% 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
3,957
Cooling degree days, base 65°F
1,358
Growing degree days, base 40°F
6,910
Growing degree days, base 45°F
5,458
Growing degree days, base 50°F
4,181
Growing degree days, base 55°F
3,074
Growing degree days, base 60°F
2,135

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January842013
February706016
March598155
April31114189
May11082438
June11257696
July0411876
August0355820
September19195626
October18942326
November460298
December713030

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 17.3 km from Nelsonia. 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 USW00093739 (Wallops Island Flight Fac). Public domain.