Westover climate

Westover Frost Dates and Growing Season

NOAA 1991-2020 normals for Morgantown L&d, 1.6 km from Westover, elevation 825 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Morgantown L&d. 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 26 and the first fall freeze around October 23, a growing season of about 180 days.

Median at 36°F
last May 6, first October 13
Median at 32°F
last April 26, first October 23
Median at 28°F
last April 14, first November 1

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 24May 18May 13May 9May 6May 2Apr 30Apr 27Apr 22
32°FMay 12May 6May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 10
28°FApr 30Apr 24Apr 20Apr 17Apr 14Apr 10Apr 7Apr 3Mar 30
24°FApr 16Apr 11Apr 7Apr 4Apr 2Mar 31Mar 28Mar 24Mar 19
20°FApr 5Apr 1Mar 29Mar 25Mar 22Mar 19Mar 15Mar 12Mar 6
16°FMar 27Mar 22Mar 17Mar 15Mar 11Mar 8Mar 4Feb 28Feb 23

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 29Oct 4Oct 7Oct 10Oct 13Oct 15Oct 18Oct 21Oct 26
32°FOct 9Oct 13Oct 17Oct 20Oct 23Oct 26Oct 29Oct 31Nov 3
28°FOct 19Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 10Nov 16
24°FNov 1Nov 3Nov 6Nov 8Nov 11Nov 14Nov 18Nov 22Nov 28
20°FNov 6Nov 10Nov 14Nov 18Nov 22Nov 27Dec 1Dec 4Dec 12
16°FNov 17Nov 22Nov 28Dec 2Dec 7Dec 11Dec 16Dec 22Dec 29

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°F179171167163159155150146137
32°F199193189184180175171166159
28°F222215210206203199195189181
24°F245238232229224220216211204
20°F274264257253248243238233224
16°F300291285279274268262255247

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
5,441
Cooling degree days, base 65°F
743
Growing degree days, base 40°F
5,460
Growing degree days, base 45°F
4,227
Growing degree days, base 50°F
3,141
Growing degree days, base 55°F
2,197
Growing degree days, base 60°F
1,393

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,09102
February91804
March781026
April4154133
May17241344
June26145569
July2249711
August5205665
September7089471
October34610180
November670032
December94405

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 1.6 km from Westover. 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 USC00466212 (Morgantown L&d). Public domain.