Eldorado Springs climate

Eldorado Springs Frost Dates and Growing Season

NOAA 1991-2020 normals for Gross Rsvr, 6.3 km from Eldorado Springs, elevation 7971 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gross Rsvr. 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 24 and the first fall freeze around September 23, a growing season of about 120 days.

Median at 36°F
last June 7, first September 13
Median at 32°F
last May 24, first September 23
Median at 28°F
last May 10, first October 3

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 23Jun 17Jun 13Jun 10Jun 7Jun 4Jun 2May 30May 26
32°FJun 10Jun 4May 31May 28May 24May 21May 17May 15May 11
28°FMay 27May 19May 15May 12May 10May 7May 5May 2Apr 30
24°FMay 13May 9May 6May 3May 1Apr 29Apr 25Apr 21Apr 17
20°FMay 6May 2Apr 29Apr 25Apr 21Apr 17Apr 14Apr 8Apr 3
16°FApr 29Apr 22Apr 17Apr 12Apr 8Apr 4Apr 1Mar 27Mar 21

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 30Sep 4Sep 7Sep 10Sep 13Sep 15Sep 18Sep 21Sep 24
32°FSep 9Sep 14Sep 17Sep 21Sep 23Sep 26Sep 29Oct 2Oct 6
28°FSep 17Sep 23Sep 26Sep 30Oct 3Oct 5Oct 8Oct 13Oct 17
24°FSep 27Oct 2Oct 6Oct 10Oct 14Oct 16Oct 20Oct 24Oct 29
20°FOct 5Oct 12Oct 17Oct 21Oct 24Oct 28Nov 1Nov 4Nov 10
16°FOct 15Oct 21Oct 25Oct 30Nov 2Nov 5Nov 10Nov 15Nov 20

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°F113107103999591878275
32°F13913212712312011511110698
28°F163156151147143139135130121
24°F185177172168163158154148141
20°F210202196190185180174167159
16°F234224217212207202196189180

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
7,765
Cooling degree days, base 65°F
90
Growing degree days, base 40°F
3,145
Growing degree days, base 45°F
2,181
Growing degree days, base 50°F
1,402
Growing degree days, base 55°F
792
Growing degree days, base 60°F
346

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14400
February1,03000
March94102
April76108
May524076
June21912254
July6447448
August11028384
September2994191
October650036
November89302
December1,13100

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 6.3 km from Eldorado Springs. 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 USC00053629 (Gross Rsvr). Public domain.