Concordia climate

Concordia Frost Dates and Growing Season

NOAA 1991-2020 normals for Concordia 1 W, 1.5 km from Concordia, elevation 1481 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Concordia 1 W. 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 21 and the first fall freeze around October 19, a growing season of about 177 days.

Median at 36°F
last May 1, first October 10
Median at 32°F
last April 21, first October 19
Median at 28°F
last April 11, first October 28

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

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 25Sep 29Oct 3Oct 6Oct 10Oct 13Oct 15Oct 18Oct 21
32°FOct 2Oct 9Oct 13Oct 16Oct 19Oct 21Oct 23Oct 26Oct 31
28°FOct 12Oct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 10
24°FOct 21Oct 28Nov 1Nov 2Nov 5Nov 8Nov 11Nov 15Nov 21
20°FOct 29Nov 3Nov 6Nov 11Nov 14Nov 18Nov 21Nov 26Dec 1
16°FNov 5Nov 11Nov 16Nov 21Nov 24Nov 27Dec 1Dec 5Dec 11

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°F177171167163159155152147141
32°F196190185181177173169165158
28°F219212207202198194190185178
24°F240233226222218214209204196
20°F260251246240236231226219212
16°F281271266261255251246238229

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
5,625
Cooling degree days, base 65°F
1,263
Growing degree days, base 40°F
6,057
Growing degree days, base 45°F
4,835
Growing degree days, base 50°F
3,751
Growing degree days, base 55°F
2,796
Growing degree days, base 60°F
1,966

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17600
February95307
March716152
April3999155
May15677396
June11256694
July1410874
August3336798
September72151531
October34122212
November719131
December1,07701

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 1.5 km from Concordia. 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 USC00141761 (Concordia 1 W). Public domain.