Warren County climate

Warren County Frost Dates and Growing Season

NOAA 1991-2020 normals for Bowling Green Warren CO AP, 3.3 km from Warren County, elevation 523 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bowling Green Warren CO AP. 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 5 and the first fall freeze around October 31, a growing season of about 208 days.

Median at 36°F
last April 16, first October 22
Median at 32°F
last April 5, first October 31
Median at 28°F
last March 24, first November 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°FMay 4Apr 28Apr 24Apr 19Apr 16Apr 13Apr 10Apr 7Apr 2
32°FApr 21Apr 15Apr 11Apr 8Apr 5Apr 2Mar 31Mar 26Mar 20
28°FApr 7Apr 2Mar 30Mar 27Mar 24Mar 20Mar 16Mar 12Mar 4
24°FMar 29Mar 22Mar 18Mar 14Mar 10Mar 6Mar 3Feb 28Feb 20
20°FMar 16Mar 10Mar 5Mar 2Feb 27Feb 22Feb 15Feb 10Feb 2
16°FMar 7Feb 28Feb 22Feb 16Feb 10Feb 5Feb 1Jan 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 9Oct 14Oct 17Oct 20Oct 22Oct 24Oct 26Oct 30Nov 2
32°FOct 20Oct 23Oct 26Oct 29Oct 31Nov 1Nov 4Nov 7Nov 11
28°FOct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 15Nov 19Nov 25
24°FNov 6Nov 11Nov 14Nov 17Nov 20Nov 24Nov 28Dec 2Dec 8
20°FNov 15Nov 22Nov 26Dec 1Dec 4Dec 8Dec 14Dec 22Dec 30
16°FNov 30Dec 5Dec 11Dec 18Dec 24Dec 28Jan 1Jan 8Jan 18

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°F207200195190186182178173165
32°F229222216212208204201195187
28°F256248241236232228223218211
24°F281272266261256251245240232
20°F312302295288282277270264254
16°F340331322315310304297289278

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
99% 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
3,797
Cooling degree days, base 65°F
1,676
Growing degree days, base 40°F
7,462
Growing degree days, base 45°F
6,011
Growing degree days, base 50°F
4,705
Growing degree days, base 55°F
3,547
Growing degree days, base 60°F
2,537

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January860023
February671134
March4977114
April22040295
May59150557
June3336783
July0456921
August0419883
September24217643
October20146327
November502493
December760132

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 3.3 km from Warren County. 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 USW00093808 (Bowling Green Warren CO AP). Public domain.