Westfield climate

Westfield Frost Dates and Growing Season

NOAA 1991-2020 normals for Wellsboro 4 Sw, 27.4 km from Westfield, elevation 1818 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wellsboro 4 Sw. 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 May 10 and the first fall freeze around October 5, a growing season of about 148 days.

Median at 36°F
last May 23, first September 26
Median at 32°F
last May 10, first October 5
Median at 28°F
last April 28, first October 17

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°FJun 4May 31May 28May 25May 23May 20May 17May 12May 7
32°FMay 26May 21May 17May 13May 10May 7May 4Apr 30Apr 25
28°FMay 15May 9May 5May 1Apr 28Apr 25Apr 22Apr 18Apr 14
24°FMay 3Apr 26Apr 21Apr 17Apr 15Apr 12Apr 9Apr 5Apr 2
20°FApr 15Apr 11Apr 7Apr 5Apr 3Apr 1Mar 30Mar 26Mar 21
16°FApr 5Apr 2Mar 31Mar 29Mar 26Mar 23Mar 20Mar 16Mar 11

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 13Sep 18Sep 21Sep 23Sep 26Sep 28Oct 1Oct 3Oct 7
32°FSep 23Sep 28Sep 30Oct 2Oct 5Oct 8Oct 10Oct 14Oct 20
28°FOct 3Oct 8Oct 12Oct 15Oct 17Oct 21Oct 25Oct 29Nov 2
24°FOct 15Oct 20Oct 25Oct 29Nov 1Nov 3Nov 7Nov 11Nov 17
20°FOct 30Nov 2Nov 6Nov 10Nov 13Nov 17Nov 20Nov 24Dec 1
16°FNov 10Nov 15Nov 19Nov 22Nov 25Nov 29Dec 1Dec 6Dec 12

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°F145138133129125122118114107
32°F167161155152148144139135128
28°F193187182176172167163157148
24°F220213208204199194189182174
20°F243236232228224219215210203
16°F266256251246243240236231226

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
7,378
Cooling degree days, base 65°F
306
Growing degree days, base 40°F
4,012
Growing degree days, base 45°F
2,982
Growing degree days, base 50°F
2,091
Growing degree days, base 55°F
1,336
Growing degree days, base 60°F
731

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33000
February1,15400
March1,03207
April634252
May32016204
June10459407
July32118552
August5083498
September20525282
October533379
November834010
December1,15201

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 27.4 km from Westfield. 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 USC00369408 (Wellsboro 4 Sw). Public domain.