Salcha climate

Salcha Frost Dates and Growing Season

NOAA 1991-2020 normals for Eielson Fld, 18.5 km from Salcha, elevation 547 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Eielson Fld. 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 20 and the first fall freeze around September 1, a growing season of about 104 days.

Median at 36°F
last May 31, first August 22
Median at 32°F
last May 20, first September 1
Median at 28°F
last May 10, first September 14

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 18Jun 10Jun 5Jun 2May 31May 29May 26May 23May 19
32°FJun 3May 29May 25May 22May 20May 18May 15May 13May 10
28°FMay 25May 18May 15May 12May 10May 8May 6May 3May 1
24°FMay 12May 8May 5May 3May 1Apr 29Apr 26Apr 22Apr 17
20°FMay 5May 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10
16°FApr 30Apr 24Apr 22Apr 19Apr 16Apr 14Apr 11Apr 8Apr 6

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 10Aug 14Aug 17Aug 20Aug 22Aug 24Aug 27Aug 29Sep 2
32°FAug 20Aug 25Aug 27Aug 30Sep 1Sep 3Sep 6Sep 10Sep 16
28°FSep 1Sep 4Sep 7Sep 11Sep 14Sep 18Sep 20Sep 23Sep 27
24°FSep 10Sep 16Sep 19Sep 22Sep 25Sep 28Sep 30Oct 2Oct 7
20°FSep 19Sep 24Sep 28Sep 30Oct 2Oct 4Oct 7Oct 10Oct 13
16°FSep 26Sep 30Oct 3Oct 6Oct 8Oct 11Oct 13Oct 16Oct 19

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°F999389868279747063
32°F121115111107104100969185
28°F143137133130126123119115108
24°F163158153150147143140135129
20°F179173169164161158154150144
16°F190184181177173170167163157

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
13,878
Cooling degree days, base 65°F
34
Growing degree days, base 40°F
2,177
Growing degree days, base 45°F
1,463
Growing degree days, base 50°F
868
Growing degree days, base 55°F
434
Growing degree days, base 60°F
162

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January2,29200
February1,82300
March1,66600
April96202
May523059
June19514273
July14115340
August3154172
September630021
October1,25601
November1,88400
December2,19200

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 18.5 km from Salcha. 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 USC00502707 (Eielson Fld). Public domain.