Sanders climate

Sanders Frost Dates and Growing Season

NOAA 1991-2020 normals for Sanders, 1.4 km from Sanders, elevation 5853 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sanders. 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 22 and the first fall freeze around October 8, a growing season of about 138 days.

Median at 36°F
last June 4, first October 1
Median at 32°F
last May 22, first October 8
Median at 28°F
last May 7, first October 17

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

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 17Sep 22Sep 25Sep 28Oct 1Oct 3Oct 5Oct 9Oct 13
32°FSep 25Sep 30Oct 2Oct 5Oct 8Oct 11Oct 15Oct 18Oct 22
28°FSep 30Oct 6Oct 10Oct 14Oct 17Oct 20Oct 23Oct 27Nov 2
24°FOct 10Oct 16Oct 21Oct 24Oct 27Oct 30Nov 2Nov 6Nov 12
20°FOct 21Oct 27Oct 31Nov 3Nov 6Nov 10Nov 14Nov 18Nov 23
16°FOct 29Nov 5Nov 10Nov 13Nov 17Nov 20Nov 23Nov 27Dec 2

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°F13612912412111711210810497
32°F161153147142138133128123115
28°F184177171166161156150144133
24°F211203197191185180174166154
20°F241231225220214210203197187
16°F273264257251246241234228219

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
5,275
Cooling degree days, base 65°F
641
Growing degree days, base 40°F
5,155
Growing degree days, base 45°F
3,900
Growing degree days, base 50°F
2,843
Growing degree days, base 55°F
1,953
Growing degree days, base 60°F
1,219

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98100
February77401
March68109
April471065
May2398247
June4097507
July1258722
August2215677
September6162452
October3611150
November692012
December97300

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 1.4 km from Sanders. 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 USC00027488 (Sanders). Public domain.