Pe Ell climate

Pe Ell Frost Dates and Growing Season

NOAA 1991-2020 normals for Grays Rvr Hatchery, 28.6 km from Pe Ell, elevation 100 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Grays Rvr Hatchery. 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 27 and the first fall freeze around October 22, a growing season of about 178 days.

Median at 36°F
last May 17, first October 3
Median at 32°F
last April 27, first October 22
Median at 28°F
last March 25, first November 12

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 7May 31May 28May 22May 17May 12May 7May 2Apr 27
32°FMay 18May 9May 4Apr 30Apr 27Apr 22Apr 17Apr 11Apr 2
28°FApr 20Apr 11Apr 4Mar 31Mar 25Mar 17Mar 10Feb 28Feb 20
24°FMar 21Mar 5Feb 28Feb 24Feb 19Feb 11Jan 31Jan 11Dec 21
20°FMar 2Feb 25Feb 16Feb 4Jan 28Jan 10Dec 31Dec 16Dec 3
16°FFeb 23Feb 12Feb 1Jan 21Jan 8Jan 1Dec 29Dec 10Dec 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 15Sep 23Sep 28Oct 1Oct 3Oct 6Oct 10Oct 15Oct 22
32°FOct 3Oct 8Oct 15Oct 19Oct 22Oct 26Oct 29Nov 3Nov 11
28°FOct 22Oct 28Nov 1Nov 7Nov 12Nov 18Nov 25Dec 2Dec 16
24°FNov 8Nov 17Nov 25Dec 2Dec 10Dec 22Jan 1Jan 13Feb 8
20°FNov 24Dec 1Dec 8Dec 21Dec 30Jan 8Jan 23Feb 9Feb 21
16°FDec 1Dec 8Dec 27Jan 1Jan 3Jan 17Jan 26Feb 4Feb 20

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°F167157150145138132126120111
32°F209198190183178172165158148
28°F277266252244236228220210197
24°F351334322311303294280270253
20°F365365365365359343334320307
16°F365365365365365365365365346

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
93% of years
20°F or colder
54% of years
16°F or colder
15% 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
4,985
Cooling degree days, base 65°F
112
Growing degree days, base 40°F
4,380
Growing degree days, base 45°F
2,895
Growing degree days, base 50°F
1,753
Growing degree days, base 55°F
926
Growing degree days, base 60°F
383

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January72103
February60106
March608017
April476052
May3215163
June21212254
July9542412
August8436417
September16516303
October3911109
November587015
December72702

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 28.6 km from Pe Ell. 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 USC00453333 (Grays Rvr Hatchery). Public domain.