Homer climate

Homer Frost Dates and Growing Season

NOAA 1991-2020 normals for Homer 1N, 2.1 km from Homer, elevation 215 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Homer 1N. 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 March 30 and the first fall freeze around November 6, a growing season of about 221 days.

Median at 36°F
last April 11, first October 28
Median at 32°F
last March 30, first November 6
Median at 28°F
last March 14, first November 16

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°FApr 29Apr 23Apr 19Apr 15Apr 11Apr 7Apr 4Mar 31Mar 23
32°FApr 16Apr 9Apr 5Apr 2Mar 30Mar 26Mar 22Mar 16Mar 9
28°FApr 2Mar 27Mar 22Mar 17Mar 14Mar 10Mar 6Feb 28Feb 24
24°FMar 17Mar 12Mar 8Mar 4Feb 28Feb 25Feb 19Feb 9Jan 30
20°FMar 11Mar 4Feb 27Feb 20Feb 9Feb 1Jan 27Jan 18Jan 6
16°FMar 2Feb 20Feb 4Jan 31Jan 25Jan 19Jan 12Jan 5Dec 29

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°FOct 14Oct 19Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 10
32°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 8Nov 11Nov 16Nov 22
28°FNov 1Nov 6Nov 10Nov 12Nov 16Nov 20Nov 24Nov 30Dec 5
24°FNov 9Nov 16Nov 21Nov 26Dec 1Dec 4Dec 9Dec 16Dec 27
20°FNov 23Dec 1Dec 6Dec 13Dec 22Dec 29Jan 2Jan 8Jan 21
16°FDec 8Dec 20Dec 29Jan 2Jan 5Jan 9Jan 15Jan 22Feb 6

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°F223214208204199195190185178
32°F248238232226221216210206197
28°F276267260253248242236230221
24°F313300291285278272265257248
20°F354341332323314304297288274
16°F365365365360352343335324304

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
96% of years
16°F or colder
69% 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
2,774
Cooling degree days, base 65°F
2,010
Growing degree days, base 40°F
8,527
Growing degree days, base 45°F
6,921
Growing degree days, base 50°F
5,459
Growing degree days, base 55°F
4,149
Growing degree days, base 60°F
2,992

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January659253
February494480
March33815204
April14056374
May26192631
June0375825
July0490955
August0480945
September10299739
October13182424
November37812160
December599370

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 2.1 km from Homer. 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 USC00164355 (Homer 1N). Public domain.