Pierson climate

Pierson Frost Dates and Growing Season

NOAA 1991-2020 normals for Crescent City, 21.2 km from Pierson, elevation 53 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Crescent City. 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 February 1 and the first fall freeze around January 8, a growing season of about 334 days.

Median at 36°F
last February 18, first December 23
Median at 32°F
last February 1, first January 8
Median at 28°F
last January 22, first January 16

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°FMar 15Mar 6Feb 28Feb 23Feb 18Feb 12Feb 6Jan 31Jan 19
32°FFeb 28Feb 20Feb 13Feb 6Feb 1Jan 27Jan 20Jan 13Jan 3
28°FFeb 16Feb 8Feb 1Jan 28Jan 22Jan 18Jan 14Jan 8Jan 1
24°FFeb 6Jan 30Jan 25Jan 22Jan 20Jan 16Jan 12Jan 9Dec 31
20°F–––––––––
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°FNov 28Dec 3Dec 9Dec 16Dec 23Dec 31Jan 4Jan 11Jan 23
32°FDec 10Dec 22Dec 31Jan 3Jan 8Jan 14Jan 19Jan 29Feb 7
28°FDec 27Jan 2Jan 7Jan 11Jan 16Jan 20Jan 24Jan 31Feb 9
24°FDec 26Jan 7Jan 11Jan 15Jan 19Jan 21Jan 24Jan 28Feb 1
20°F–––––––––
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°F337326316310304297290283272
32°F365361350342334327319311302
28°F365365365365365360350338327
24°F365365365365365365365365357
20°F365365365365365365365365365
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
98% of years
32°F or colder
80% of years
28°F or colder
41% of years
24°F or colder
12% of years
20°F or colder
2% of years
16°F or colder
0% 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
814
Cooling degree days, base 65°F
3,118
Growing degree days, base 40°F
11,432
Growing degree days, base 45°F
9,622
Growing degree days, base 50°F
7,844
Growing degree days, base 55°F
6,139
Growing degree days, base 60°F
4,547

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January25824261
February16639304
March9288463
April20186617
May1350814
June0470920
July05361,001
August05431,008
September0456906
October10283738
November7599476
December19245337

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 21.2 km from Pierson. 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 USC00081978 (Crescent City). Public domain.