Eldora climate

Eldora Frost Dates and Growing Season

NOAA 1991-2020 normals for Eldora, 0.5 km from Eldora, elevation 1073 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Eldora. 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 27 and the first fall freeze around October 10, a growing season of about 165 days.

Median at 36°F
last May 5, first October 1
Median at 32°F
last April 27, first October 10
Median at 28°F
last April 16, first October 21

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 17May 12May 9May 7May 5May 3May 1Apr 28Apr 21
32°FMay 8May 4May 2Apr 30Apr 27Apr 23Apr 20Apr 17Apr 13
28°FMay 1Apr 25Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 3
24°FApr 21Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1Mar 30Mar 22
20°FApr 13Apr 8Apr 4Apr 1Mar 30Mar 26Mar 22Mar 18Mar 12
16°FApr 4Mar 31Mar 27Mar 23Mar 20Mar 17Mar 13Mar 9Mar 5

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 18Sep 22Sep 25Sep 28Oct 1Oct 3Oct 5Oct 9Oct 13
32°FSep 27Oct 1Oct 4Oct 7Oct 10Oct 12Oct 15Oct 19Oct 22
28°FOct 5Oct 11Oct 15Oct 18Oct 21Oct 23Oct 26Oct 29Nov 1
24°FOct 17Oct 22Oct 25Oct 28Oct 30Nov 1Nov 3Nov 7Nov 12
20°FOct 27Oct 31Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 22
16°FNov 1Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 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°F164158154150147144141137131
32°F183178173169165162158153147
28°F205197193189186182178173167
24°F225218213208205201197192185
20°F245238231227223218213208201
16°F262256250245241237232227219

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
7,269
Cooling degree days, base 65°F
727
Growing degree days, base 40°F
4,874
Growing degree days, base 45°F
3,811
Growing degree days, base 50°F
2,861
Growing degree days, base 55°F
2,025
Growing degree days, base 60°F
1,310

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,48500
February1,21400
March958015
April543381
May22343306
June32166584
July6245704
August17186634
September13474398
October4759125
November888015
December1,29301

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 0.5 km from Eldora. 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 USC00132573 (Eldora). Public domain.