Cheney climate

Cheney Frost Dates and Growing Season

NOAA 1991-2020 normals for Norwich, 20.3 km from Cheney, elevation 1501 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Norwich. 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 12 and the first fall freeze around October 29, a growing season of about 201 days.

Median at 36°F
last April 21, first October 20
Median at 32°F
last April 12, first October 29
Median at 28°F
last April 2, first November 7

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 2Apr 30Apr 27Apr 24Apr 21Apr 18Apr 16Apr 13Apr 8
32°FApr 25Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 1Mar 28
28°FApr 18Apr 12Apr 8Apr 5Apr 2Mar 30Mar 27Mar 22Mar 16
24°FApr 7Apr 2Mar 30Mar 27Mar 23Mar 20Mar 16Mar 11Mar 5
20°FMar 30Mar 24Mar 19Mar 16Mar 12Mar 8Mar 4Mar 1Feb 23
16°FMar 19Mar 13Mar 9Mar 5Mar 1Feb 27Feb 22Feb 17Feb 7

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 4Oct 10Oct 15Oct 17Oct 20Oct 22Oct 25Oct 29Nov 3
32°FOct 16Oct 21Oct 24Oct 27Oct 29Nov 1Nov 3Nov 7Nov 11
28°FOct 24Oct 30Nov 1Nov 4Nov 7Nov 9Nov 12Nov 15Nov 20
24°FOct 31Nov 4Nov 8Nov 11Nov 14Nov 17Nov 20Nov 24Nov 30
20°FNov 7Nov 13Nov 17Nov 20Nov 23Nov 26Nov 29Dec 3Dec 9
16°FNov 17Nov 21Nov 26Nov 29Dec 3Dec 7Dec 11Dec 16Dec 23

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°F201195189185181178174169162
32°F220213208204201197193188181
28°F237231226222217213209205198
24°F260253246241235232227222214
20°F279271266261255251246240232
16°F303294287282276272267260251

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
4,591
Cooling degree days, base 65°F
1,645
Growing degree days, base 40°F
6,975
Growing degree days, base 45°F
5,631
Growing degree days, base 50°F
4,430
Growing degree days, base 55°F
3,367
Growing degree days, base 60°F
2,440

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00402
February790015
March594279
April30616210
May88117496
June4333778
July0481945
August1435899
September32220638
October23641301
November594161
December94206

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 20.3 km from Cheney. 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 USC00145870 (Norwich). Public domain.