Garden County climate

Garden County Frost Dates and Growing Season

NOAA 1991-2020 normals for Crescent Lake NWR, 17.9 km from Garden County, elevation 3818 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Crescent Lake NWR. 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 September 29, a growing season of about 139 days.

Median at 36°F
last May 24, first September 20
Median at 32°F
last May 13, first September 29
Median at 28°F
last May 2, first October 9

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 2May 29May 26May 24May 21May 19May 15May 11
32°FMay 26May 22May 18May 15May 13May 10May 7May 4May 1
28°FMay 15May 11May 7May 5May 2Apr 30Apr 28Apr 24Apr 18
24°FMay 6May 2Apr 29Apr 26Apr 23Apr 19Apr 15Apr 12Apr 6
20°FApr 28Apr 22Apr 17Apr 13Apr 10Apr 6Apr 3Mar 31Mar 25
16°FApr 16Apr 11Apr 7Apr 3Apr 1Mar 28Mar 24Mar 18Mar 12

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 5Sep 11Sep 14Sep 17Sep 20Sep 22Sep 26Sep 29Oct 3
32°FSep 16Sep 20Sep 24Sep 27Sep 29Oct 2Oct 5Oct 8Oct 12
28°FSep 26Sep 30Oct 3Oct 6Oct 9Oct 11Oct 15Oct 18Oct 23
24°FOct 5Oct 10Oct 14Oct 17Oct 19Oct 21Oct 24Oct 27Nov 1
20°FOct 13Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 8
16°FOct 19Oct 25Oct 28Oct 31Nov 3Nov 6Nov 9Nov 13Nov 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°F13713112612211811411010698
32°F156150146142139135130125118
28°F176169165161158154150146139
24°F199192187182178175170165160
20°F221213206202197194190184179
16°F243234228223219213207202194

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
6,918
Cooling degree days, base 65°F
610
Growing degree days, base 40°F
4,586
Growing degree days, base 45°F
3,499
Growing degree days, base 50°F
2,564
Growing degree days, base 55°F
1,777
Growing degree days, base 60°F
1,123

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,23500
February1,03601
March854015
April581162
May31915216
June73100479
July11236689
August23198640
September16758357
October531292
November878012
December1,21000

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 17.9 km from Garden 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 USC00252000 (Crescent Lake NWR). Public domain.