Kodiak climate

Kodiak Frost Dates and Growing Season

NOAA 1991-2020 normals for Kodiak Wwtp, 3.4 km from Kodiak, elevation 54 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kodiak Wwtp. 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 29 and the first fall freeze around October 14, a growing season of about 168 days.

Median at 36°F
last May 19, first October 1
Median at 32°F
last April 29, first October 14
Median at 28°F
last April 11, first October 26

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

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 14Sep 21Sep 24Sep 28Oct 1Oct 2Oct 6Oct 10Oct 16
32°FSep 30Oct 4Oct 7Oct 11Oct 14Oct 17Oct 19Oct 23Oct 29
28°FOct 11Oct 16Oct 19Oct 22Oct 26Oct 29Nov 1Nov 7Nov 14
24°FOct 21Oct 27Nov 1Nov 3Nov 7Nov 11Nov 17Nov 22Dec 1
20°FNov 1Nov 6Nov 11Nov 17Nov 21Nov 25Dec 1Dec 6Dec 16
16°FNov 9Nov 18Nov 24Nov 29Dec 3Dec 9Dec 16Dec 26Jan 4

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°F155148143138135130126120112
32°F190183177172168164160156149
28°F220212206202197193188182177
24°F248236230225219214210204197
20°F276263254248241234228220211
16°F307294284276268259251243230

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
8,430
Cooling degree days, base 65°F
3
Growing degree days, base 40°F
1,866
Growing degree days, base 45°F
1,018
Growing degree days, base 50°F
435
Growing degree days, base 55°F
125
Growing degree days, base 60°F
22

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,03700
February90200
March99000
April79500
May63409
June446051
July3171154
August2952173
September443048
October70101
November86400
December1,00800

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 3.4 km from Kodiak. 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 USC00504991 (Kodiak Wwtp). Public domain.