Chester climate

Chester Frost Dates and Growing Season

NOAA 1991-2020 normals for Chester, 0.3 km from Chester, elevation 3132 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chester. 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 24 and the first fall freeze around September 17, a growing season of about 115 days.

Median at 36°F
last June 9, first September 5
Median at 32°F
last May 24, first September 17
Median at 28°F
last May 11, first September 26

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°FJul 1Jun 23Jun 18Jun 13Jun 9Jun 5Jun 2May 29May 24
32°FJun 9Jun 2May 29May 27May 24May 22May 19May 16May 11
28°FMay 26May 20May 16May 13May 11May 9May 7May 4Apr 30
24°FMay 12May 8May 6May 4May 2Apr 30Apr 27Apr 23Apr 18
20°FMay 4Apr 30Apr 28Apr 24Apr 20Apr 17Apr 13Apr 9Apr 4
16°FApr 27Apr 21Apr 16Apr 13Apr 9Apr 6Apr 3Apr 1Mar 25

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°FAug 20Aug 26Aug 31Sep 3Sep 5Sep 8Sep 11Sep 14Sep 18
32°FSep 3Sep 7Sep 11Sep 15Sep 17Sep 19Sep 22Sep 24Sep 29
28°FSep 14Sep 19Sep 22Sep 24Sep 26Sep 29Oct 1Oct 3Oct 8
24°FSep 20Sep 25Sep 28Oct 1Oct 3Oct 5Oct 8Oct 11Oct 15
20°FSep 27Oct 1Oct 5Oct 8Oct 11Oct 14Oct 17Oct 20Oct 24
16°FOct 3Oct 8Oct 13Oct 16Oct 19Oct 22Oct 25Oct 27Oct 31

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°F10810194898580746858
32°F13312712311911511110610193
28°F153147143140137134131126118
24°F172165161158154151147144139
20°F193186182177173169165159153
16°F215206201196192189184178170

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
8,848
Cooling degree days, base 65°F
257
Growing degree days, base 40°F
3,426
Growing degree days, base 45°F
2,503
Growing degree days, base 50°F
1,719
Growing degree days, base 55°F
1,075
Growing degree days, base 60°F
582

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,53000
February1,27100
March1,07402
April705019
May4085135
June18922290
July53118530
August7399493
September29012213
October712036
November1,10601
December1,43800

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 0.3 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 USC00241692 (Chester). Public domain.