Bell Hill climate

Bell Hill Frost Dates and Growing Season

NOAA 1991-2020 normals for Sequim 2 E, 3.6 km from Bell Hill, elevation 50 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sequim 2 E. 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 21 and the first fall freeze around October 20, a growing season of about 181 days.

Median at 36°F
last May 7, first October 3
Median at 32°F
last April 21, first October 20
Median at 28°F
last March 28, first November 7

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 26May 19May 14May 11May 7May 3Apr 30Apr 28Apr 24
32°FMay 7May 1Apr 28Apr 24Apr 21Apr 16Apr 13Apr 9Apr 3
28°FApr 17Apr 10Apr 4Mar 31Mar 28Mar 23Mar 17Mar 11Mar 2
24°FMar 25Mar 13Mar 4Feb 28Feb 24Feb 19Feb 13Feb 1Jan 11
20°FFeb 28Feb 21Feb 13Feb 4Jan 24Jan 13Jan 2Dec 21Dec 5
16°FFeb 15Feb 5Jan 26Jan 13Jan 3Dec 29Dec 19Dec 6Nov 27

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 20Sep 24Sep 28Oct 1Oct 3Oct 5Oct 9Oct 13Oct 17
32°FOct 3Oct 8Oct 13Oct 17Oct 20Oct 22Oct 25Oct 30Nov 3
28°FOct 19Oct 26Oct 30Nov 2Nov 7Nov 10Nov 15Nov 22Dec 1
24°FNov 4Nov 12Nov 19Nov 24Nov 29Dec 2Dec 8Dec 17Dec 29
20°FNov 18Nov 26Dec 1Dec 6Dec 14Dec 21Dec 31Jan 10Feb 2
16°FNov 20Nov 30Dec 7Dec 16Dec 25Jan 1Jan 9Jan 19Feb 7

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°F167160155150146141137131122
32°F205197191186181176171165157
28°F257245238231225219212205195
24°F324308296288278269260252239
20°F365362351338331322313303286
16°F365365365365365363347334321

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
85% of years
16°F or colder
42% 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
5,887
Cooling degree days, base 65°F
21
Growing degree days, base 40°F
3,525
Growing degree days, base 45°F
2,220
Growing degree days, base 50°F
1,249
Growing degree days, base 55°F
559
Growing degree days, base 60°F
153

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January79801
February70101
March68503
April545020
May3770113
June2392214
July14210333
August1408334
September2691186
October505040
November67504
December81101

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 3.6 km from Bell Hill. 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 USC00457544 (Sequim 2 E). Public domain.