Enumclaw climate

Enumclaw Frost Dates and Growing Season

NOAA 1991-2020 normals for Buckley 1 Ne, 4 km from Enumclaw, elevation 685 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Buckley 1 Ne. 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 7 and the first fall freeze around October 30, a growing season of about 204 days.

Median at 36°F
last May 1, first October 11
Median at 32°F
last April 7, first October 30
Median at 28°F
last March 8, first November 21

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 19May 12May 8May 4May 1Apr 29Apr 25Apr 21Apr 15
32°FApr 27Apr 20Apr 15Apr 11Apr 7Apr 3Mar 30Mar 26Mar 16
28°FMar 31Mar 25Mar 19Mar 13Mar 8Mar 2Feb 27Feb 21Feb 11
24°FMar 8Feb 28Feb 22Feb 16Feb 8Jan 31Jan 20Jan 7Dec 26
20°FFeb 23Feb 13Jan 31Jan 21Jan 12Jan 4Dec 28Dec 14Dec 4
16°FFeb 12Jan 30Jan 16Jan 6Jan 1Dec 25Dec 16Dec 9Dec 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 28Oct 2Oct 5Oct 8Oct 11Oct 15Oct 18Oct 23Oct 31
32°FOct 8Oct 16Oct 20Oct 25Oct 30Nov 2Nov 7Nov 13Nov 22
28°FOct 26Nov 2Nov 9Nov 14Nov 21Nov 25Nov 29Dec 5Dec 15
24°FNov 11Nov 22Nov 29Dec 2Dec 8Dec 15Dec 22Dec 29Jan 13
20°FNov 26Dec 2Dec 7Dec 13Dec 21Dec 29Jan 4Jan 17Feb 5
16°FNov 30Dec 6Dec 10Dec 18Dec 27Jan 1Jan 6Jan 18Feb 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°F189178172167162158152146139
32°F233223216209204198191185174
28°F295281271265258250243235224
24°F353339327317308301293282269
20°F365365365360350341334320307
16°F365365365365365365364351334

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
96% of years
20°F or colder
68% of years
16°F or colder
31% 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
5,241
Cooling degree days, base 65°F
119
Growing degree days, base 40°F
4,238
Growing degree days, base 45°F
2,826
Growing degree days, base 50°F
1,741
Growing degree days, base 55°F
947
Growing degree days, base 60°F
405

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January76003
February65104
March634015
April494045
May3262156
June20012263
July7449440
August7045440
September17810283
October444077
November626013
December78601

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 4 km from Enumclaw. 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 USC00450945 (Buckley 1 Ne). Public domain.