Douglas County climate

Douglas County Frost Dates and Growing Season

NOAA 1991-2020 normals for Minden, 14.6 km from Douglas County, elevation 4709 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Minden. 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 30 and the first fall freeze around September 26, a growing season of about 119 days.

Median at 36°F
last June 12, first September 9
Median at 32°F
last May 30, first September 26
Median at 28°F
last May 6, first October 8

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 30Jun 23Jun 18Jun 15Jun 12Jun 8Jun 6Jun 3May 29
32°FJun 14Jun 8Jun 4Jun 1May 30May 25May 21May 15May 8
28°FMay 29May 22May 16May 10May 6May 3Apr 30Apr 27Apr 23
24°FMay 8May 1Apr 28Apr 25Apr 21Apr 18Apr 15Apr 11Apr 6
20°FApr 21Apr 16Apr 11Apr 8Apr 5Apr 1Mar 29Mar 23Mar 15
16°FApr 5Mar 31Mar 24Mar 18Mar 13Mar 7Mar 4Feb 28Feb 20

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°FAug 24Aug 31Sep 3Sep 6Sep 9Sep 12Sep 16Sep 19Sep 24
32°FSep 9Sep 15Sep 19Sep 23Sep 26Sep 29Oct 1Oct 5Oct 9
28°FSep 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 17Oct 22
24°FOct 6Oct 11Oct 14Oct 17Oct 20Oct 23Oct 25Oct 29Nov 2
20°FOct 16Oct 20Oct 24Oct 27Oct 31Nov 1Nov 4Nov 8Nov 13
16°FOct 25Nov 1Nov 3Nov 6Nov 10Nov 13Nov 16Nov 20Nov 26

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°F11010296928883777162
32°F14213312812411911410910396
28°F172166160156151147142135128
24°F200193188184180176172168160
20°F232222216210206201197192185
16°F269259251246240235228221212

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
5,805
Cooling degree days, base 65°F
385
Growing degree days, base 40°F
4,536
Growing degree days, base 45°F
3,331
Growing degree days, base 50°F
2,329
Growing degree days, base 55°F
1,520
Growing degree days, base 60°F
875

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January99800
February79102
March698014
April537048
May3126194
June10852399
July12170623
August19126572
September12731358
October4331109
November75608
December1,01502

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 14.6 km from Douglas 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 USC00265191 (Minden). Public domain.