Weston climate

Weston Frost Dates and Growing Season

NOAA 1991-2020 normals for Stonewall Jackson Dam, 3.8 km from Weston, elevation 1045 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stonewall Jackson Dam. 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 179 days.

Median at 36°F
last May 6, first October 12
Median at 32°F
last April 26, first October 23
Median at 28°F
last April 15, first October 31

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 23May 17May 12May 9May 6May 2Apr 30Apr 26Apr 22
32°FMay 13May 6May 2Apr 30Apr 26Apr 23Apr 20Apr 18Apr 15
28°FApr 29Apr 23Apr 20Apr 17Apr 15Apr 12Apr 9Apr 4Mar 31
24°FApr 16Apr 12Apr 8Apr 4Apr 2Mar 31Mar 28Mar 23Mar 17
20°FApr 5Apr 1Mar 29Mar 26Mar 21Mar 18Mar 14Mar 10Mar 3
16°FMar 30Mar 23Mar 17Mar 13Mar 10Mar 5Mar 1Feb 26Feb 15

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 7Oct 10Oct 12Oct 15Oct 17Oct 21Oct 25
32°FOct 8Oct 13Oct 16Oct 19Oct 23Oct 25Oct 28Oct 31Nov 3
28°FOct 16Oct 22Oct 25Oct 28Oct 31Nov 1Nov 4Nov 8Nov 13
24°FOct 26Oct 31Nov 2Nov 6Nov 9Nov 12Nov 16Nov 20Nov 27
20°FNov 4Nov 9Nov 14Nov 17Nov 21Nov 26Dec 1Dec 5Dec 13
16°FNov 14Nov 21Nov 28Dec 1Dec 6Dec 11Dec 17Dec 22Dec 28

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°F177172168164160156152147139
32°F196190186182179175171166158
28°F219212209204201197192188179
24°F243235230226222218213208200
20°F274263256251246240234228220
16°F304294286280273267261254244

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
5,173
Cooling degree days, base 65°F
875
Growing degree days, base 40°F
5,772
Growing degree days, base 45°F
4,496
Growing degree days, base 50°F
3,367
Growing degree days, base 55°F
2,390
Growing degree days, base 60°F
1,560

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05207
February86907
March738036
April3939155
May15161383
June19174605
July1273736
August3243705
September67103487
October33413195
November641040
December905012

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 3.8 km from Weston. 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 USC00468522 (Stonewall Jackson Dam). Public domain.