Grayland climate

Grayland Frost Dates and Growing Season

NOAA 1991-2020 normals for Grayland, 1.1 km from Grayland, elevation 10 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Grayland. 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 29 and the first fall freeze around November 7, a growing season of about 224 days.

Median at 36°F
last April 29, first October 16
Median at 32°F
last March 29, first November 7
Median at 28°F
last February 22, first December 1

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 27May 14May 8May 3Apr 29Apr 25Apr 20Apr 13Apr 6
32°FApr 24Apr 15Apr 6Apr 1Mar 29Mar 24Mar 18Mar 11Feb 28
28°FMar 24Mar 12Mar 2Feb 27Feb 22Feb 17Feb 10Jan 30Jan 11
24°FFeb 23Feb 17Feb 9Jan 31Jan 21Jan 11Jan 2Dec 20Dec 7
20°FFeb 14Feb 1Jan 20Jan 11Jan 3Dec 28Dec 18Dec 9Dec 3
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 25Oct 1Oct 6Oct 11Oct 16Oct 19Oct 24Oct 30Nov 5
32°FOct 19Oct 24Oct 29Nov 1Nov 7Nov 12Nov 19Nov 24Dec 1
28°FNov 2Nov 12Nov 21Nov 27Dec 1Dec 6Dec 12Dec 23Jan 8
24°FNov 22Dec 1Dec 6Dec 12Dec 20Dec 31Jan 9Jan 25Feb 9
20°FNov 30Dec 7Dec 12Dec 20Dec 31Jan 4Jan 14Jan 26Feb 11
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°F200191183177171165159151138
32°F258246236229224218210202190
28°F330314304295284275267255242
24°F365365365352342332324313304
20°F365365365365365365365355339
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
99% of years
24°F or colder
70% of years
20°F or colder
27% of years
16°F or colder
3% 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
5,191
Cooling degree days, base 65°F
12
Growing degree days, base 40°F
4,038
Growing degree days, base 45°F
2,487
Growing degree days, base 50°F
1,304
Growing degree days, base 55°F
517
Growing degree days, base 60°F
103

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January68003
February58507
March591015
April488035
May3731107
June2531199
July1862281
August1603308
September2225236
October403094
November561018
December69002

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 1.1 km from Grayland. 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 USC00453320 (Grayland). Public domain.