Seaside climate

Seaside Frost Dates and Growing Season

NOAA 1991-2020 normals for Seaside, 0.7 km from Seaside, elevation 10 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Seaside. 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 2 and the first fall freeze around November 12, a growing season of about 223 days.

Median at 36°F
last April 29, first October 20
Median at 32°F
last April 2, first November 12
Median at 28°F
last February 27, first December 4

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°FMay 16May 11May 6May 2Apr 29Apr 26Apr 21Apr 15Apr 5
32°FApr 29Apr 20Apr 11Apr 6Apr 2Mar 29Mar 23Mar 16Mar 4
28°FMar 31Mar 21Mar 12Mar 5Feb 27Feb 21Feb 12Jan 29Dec 31
24°FMar 1Feb 23Feb 11Jan 30Jan 14Dec 31Dec 18Dec 9Dec 2
20°FFeb 22Feb 1Jan 8Dec 31Dec 23Dec 16Dec 12Dec 7Dec 1
16°F–––––––––

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 30Oct 5Oct 10Oct 16Oct 20Oct 23Oct 28Nov 1Nov 12
32°FOct 18Oct 26Nov 1Nov 5Nov 12Nov 18Nov 24Nov 30Dec 6
28°FNov 7Nov 17Nov 25Nov 30Dec 4Dec 10Dec 19Jan 3Feb 1
24°FNov 25Dec 1Dec 6Dec 11Dec 17Dec 29Jan 10Jan 31Feb 20
20°FNov 30Dec 5Dec 10Dec 13Dec 19Dec 23Jan 4Jan 31Feb 22
16°F–––––––––

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°F207195188182176170165158148
32°F264249239230223216209200189
28°F336316304294285275264253240
24°F365365365365351340329314297
20°F365365365365365365365365343
16°F365365365365365365365365365

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
96% of years
24°F or colder
59% of years
20°F or colder
14% of years
16°F or colder
1% 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
4,858
Cooling degree days, base 65°F
12
Growing degree days, base 40°F
4,330
Growing degree days, base 45°F
2,696
Growing degree days, base 50°F
1,402
Growing degree days, base 55°F
537
Growing degree days, base 60°F
105

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January603016
February546014
March564023
April480035
May3731108
June2630188
July1871279
August1593308
September2066252
October3541130
November498040
December625010

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 0.7 km from Seaside. 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 USC00357641 (Seaside). Public domain.