Central City climate

Central City Frost Dates and Growing Season

NOAA 1991-2020 normals for Coggon, 8.4 km from Central City, elevation 903 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Coggon. 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 3 and the first fall freeze around October 7, a growing season of about 156 days.

Median at 36°F
last May 12, first September 27
Median at 32°F
last May 3, first October 7
Median at 28°F
last April 22, first October 18

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 26May 21May 18May 15May 12May 9May 6May 3Apr 29
32°FMay 17May 12May 9May 5May 3May 1Apr 28Apr 24Apr 18
28°FMay 6May 3Apr 30Apr 26Apr 22Apr 18Apr 15Apr 11Apr 6
24°FApr 30Apr 22Apr 17Apr 13Apr 10Apr 7Apr 4Apr 1Mar 26
20°FApr 15Apr 8Apr 5Apr 2Mar 31Mar 29Mar 24Mar 20Mar 14
16°FApr 3Mar 31Mar 26Mar 23Mar 20Mar 17Mar 13Mar 9Mar 4

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 13Sep 18Sep 21Sep 24Sep 27Sep 30Oct 2Oct 6Oct 10
32°FSep 22Sep 27Sep 30Oct 4Oct 7Oct 9Oct 12Oct 16Oct 20
28°FOct 1Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 26Oct 30
24°FOct 14Oct 19Oct 22Oct 25Oct 27Oct 29Nov 1Nov 4Nov 9
20°FOct 25Oct 30Nov 1Nov 3Nov 6Nov 8Nov 12Nov 16Nov 22
16°FNov 1Nov 6Nov 9Nov 13Nov 16Nov 19Nov 23Nov 27Dec 3

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°F156148144140137134130125119
32°F176168163159156152148143136
28°F197190185181176172168163155
24°F219212207203200196191186179
20°F242234228224220216212207200
16°F263255250246241237232226218

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
7,318
Cooling degree days, base 65°F
614
Growing degree days, base 40°F
4,657
Growing degree days, base 45°F
3,602
Growing degree days, base 50°F
2,670
Growing degree days, base 55°F
1,860
Growing degree days, base 60°F
1,168

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,46600
February1,20701
March964118
April560269
May25835270
June35138554
July7218676
August19157603
September15157364
October4968107
November88209
December1,27400

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 8.4 km from Central City. 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 USC00131705 (Coggon). Public domain.