Adams County climate

Adams County Frost Dates and Growing Season

NOAA 1991-2020 normals for Byers 5 Ene, 23.3 km from Adams County, elevation 5101 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Byers 5 Ene. 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 13 and the first fall freeze around October 2, a growing season of about 142 days.

Median at 36°F
last May 24, first September 25
Median at 32°F
last May 13, first October 2
Median at 28°F
last May 2, first October 10

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 7Jun 3May 30May 27May 24May 21May 18May 15May 11
32°FMay 30May 23May 18May 15May 13May 10May 7May 4Apr 30
28°FMay 15May 10May 7May 4May 2Apr 30Apr 27Apr 23Apr 19
24°FMay 6May 2Apr 28Apr 25Apr 22Apr 19Apr 16Apr 12Apr 6
20°FApr 26Apr 21Apr 16Apr 13Apr 10Apr 6Apr 2Mar 29Mar 22
16°FApr 18Apr 11Apr 6Apr 3Mar 30Mar 25Mar 18Mar 14Mar 8

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 11Sep 16Sep 19Sep 22Sep 25Sep 27Sep 30Oct 2Oct 5
32°FSep 20Sep 25Sep 28Oct 1Oct 2Oct 4Oct 7Oct 10Oct 14
28°FSep 30Oct 3Oct 5Oct 7Oct 10Oct 13Oct 15Oct 17Oct 22
24°FOct 6Oct 10Oct 14Oct 16Oct 18Oct 20Oct 23Oct 26Oct 30
20°FOct 13Oct 17Oct 20Oct 23Oct 26Oct 29Oct 31Nov 4Nov 9
16°FOct 19Oct 24Oct 28Oct 31Nov 3Nov 6Nov 10Nov 14Nov 19

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°F139134130126122118114109102
32°F159153149145142138135129123
28°F178172167163160156153149143
24°F198190186182178174170166159
20°F223214208203198193189184177
16°F244235228223218213207202195

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
6,427
Cooling degree days, base 65°F
674
Growing degree days, base 40°F
4,824
Growing degree days, base 45°F
3,696
Growing degree days, base 50°F
2,725
Growing degree days, base 55°F
1,904
Growing degree days, base 60°F
1,219

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13900
February97401
March791018
April560160
May29415231
June60117508
July6268727
August13208660
September12763397
October4922109
November830013
December1,14200

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 23.3 km from Adams County. 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 USC00051179 (Byers 5 Ene). Public domain.