Chester climate

Chester Frost Dates and Growing Season

NOAA 1991-2020 normals for Stevensville 2SW, 4.3 km from Chester, elevation 10 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stevensville 2SW. 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 29 and the first fall freeze around November 12, a growing season of about 228 days.

Median at 36°F
last April 7, first November 1
Median at 32°F
last March 29, first November 12
Median at 28°F
last March 18, first November 25

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 21Apr 16Apr 12Apr 9Apr 7Apr 5Apr 2Mar 31Mar 28
32°FApr 8Apr 4Apr 2Mar 31Mar 29Mar 27Mar 23Mar 20Mar 15
28°FMar 31Mar 27Mar 24Mar 21Mar 18Mar 15Mar 12Mar 9Mar 4
24°FMar 24Mar 19Mar 15Mar 12Mar 9Mar 6Mar 3Feb 28Feb 21
20°FMar 17Mar 11Mar 7Mar 3Feb 28Feb 23Feb 18Feb 12Feb 5
16°FMar 6Feb 28Feb 23Feb 17Feb 11Feb 6Feb 2Jan 28Jan 17

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 17Oct 23Oct 27Oct 30Nov 1Nov 4Nov 6Nov 10Nov 15
32°FOct 29Nov 2Nov 5Nov 9Nov 12Nov 15Nov 18Nov 23Nov 29
28°FNov 8Nov 13Nov 17Nov 21Nov 25Nov 29Dec 2Dec 8Dec 14
24°FNov 20Nov 26Dec 1Dec 6Dec 10Dec 14Dec 20Dec 24Jan 1
20°FDec 6Dec 12Dec 18Dec 23Dec 26Dec 31Jan 4Jan 9Jan 17
16°FDec 19Dec 27Jan 1Jan 5Jan 10Jan 14Jan 18Jan 24Feb 2

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°F225219214210207204199194187
32°F250241236231228224220215209
28°F275267261257252247243238231
24°F301292286281277271265259251
20°F324315308304300296291284276
16°F352339332327321315310305298

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
95% 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
4,298
Cooling degree days, base 65°F
1,448
Growing degree days, base 40°F
6,793
Growing degree days, base 45°F
5,409
Growing degree days, base 50°F
4,193
Growing degree days, base 55°F
3,125
Growing degree days, base 60°F
2,212

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91904
February78509
March653146
April31512186
May9884452
June7298741
July0448913
August0383848
September24191616
October21230295
November501172
December784012

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 4.3 km from Chester. 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 USC00188557 (Stevensville 2SW). Public domain.