Chester climate

Chester Frost Dates and Growing Season

NOAA 1991-2020 normals for Hopewell, 15.9 km from Chester, elevation 40 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hopewell. 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 6, a growing season of about 222 days.

Median at 36°F
last April 11, first October 28
Median at 32°F
last March 31, first November 6
Median at 28°F
last March 18, first November 19

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°FApr 26Apr 20Apr 17Apr 14Apr 11Apr 8Apr 5Apr 1Mar 28
32°FApr 14Apr 9Apr 5Apr 2Mar 31Mar 28Mar 24Mar 20Mar 14
28°FApr 2Mar 29Mar 25Mar 21Mar 18Mar 14Mar 10Mar 5Feb 26
24°FMar 22Mar 16Mar 12Mar 8Mar 4Feb 28Feb 25Feb 19Feb 11
20°FMar 12Mar 5Feb 28Feb 25Feb 20Feb 13Feb 7Feb 1Jan 24
16°FMar 1Feb 22Feb 14Feb 7Feb 1Jan 30Jan 25Jan 17Jan 6

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 20Oct 23Oct 26Oct 28Oct 30Nov 1Nov 4Nov 8
32°FOct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 16Nov 22
28°FNov 2Nov 6Nov 11Nov 15Nov 19Nov 22Nov 26Dec 1Dec 8
24°FNov 12Nov 19Nov 26Nov 30Dec 3Dec 8Dec 13Dec 22Jan 2
20°FNov 28Dec 5Dec 13Dec 20Dec 25Dec 30Jan 4Jan 11Jan 22
16°FDec 12Dec 22Dec 30Jan 3Jan 8Jan 15Jan 20Jan 26Feb 5

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°F219212207203200196192188181
32°F243235230226222218214209203
28°F274264257252247242236230224
24°F307296289281276269263256247
20°F334326318311306301294286274
16°F365356347337332326319311302

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
98% of years
16°F or colder
84% 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
3,260
Cooling degree days, base 65°F
1,741
Growing degree days, base 40°F
7,864
Growing degree days, base 45°F
6,326
Growing degree days, base 50°F
4,945
Growing degree days, base 55°F
3,718
Growing degree days, base 60°F
2,647

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January750030
February600141
March4529132
April18453333
May49156572
June3337784
July0468933
August0415880
September13239676
October15256376
November4066137
December652249

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 15.9 km from Chester. 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 USC00444101 (Hopewell). Public domain.