Redway climate

Redway Frost Dates and Growing Season

NOAA 1991-2020 normals for Richardson Gr SP, 10.7 km from Redway, elevation 503 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Richardson Gr SP. 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 10 and the first fall freeze around December 1, a growing season of about 271 days.

Median at 36°F
last April 13, first November 7
Median at 32°F
last March 10, first December 1
Median at 28°F
last January 15, first December 26

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 7Apr 29Apr 22Apr 17Apr 13Apr 8Apr 3Mar 28Mar 16
32°FApr 13Apr 2Mar 27Mar 18Mar 10Feb 28Feb 17Feb 3Jan 9
28°FMar 5Feb 23Feb 6Jan 27Jan 15Jan 6Dec 31Dec 21Dec 10
24°FJan 29Jan 22Jan 15Jan 12Jan 6Jan 2Dec 29Dec 18Dec 12
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°FOct 19Oct 26Nov 1Nov 3Nov 7Nov 12Nov 17Nov 23Dec 2
32°FNov 7Nov 15Nov 21Nov 27Dec 1Dec 7Dec 12Dec 23Jan 9
28°FNov 25Dec 3Dec 10Dec 18Dec 26Jan 1Jan 7Jan 20Feb 8
24°FDec 10Dec 13Dec 23Dec 31Jan 2Jan 7Jan 13Jan 20Jan 24
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°F248233224216209202196188177
32°F331309295281271262251239224
28°F365365365361351340330315293
24°F365365365365365365365365360
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
100% of years
32°F or colder
98% of years
28°F or colder
63% of years
24°F or colder
13% of years
20°F or colder
0% 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
3,734
Cooling degree days, base 65°F
494
Growing degree days, base 40°F
5,924
Growing degree days, base 45°F
4,297
Growing degree days, base 50°F
2,942
Growing degree days, base 55°F
1,884
Growing degree days, base 60°F
1,078

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January63708
February528013
March477059
April3541125
May19520293
June7649423
July9160615
August7171629
September4186495
October2437235
November506036
December66209

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 10.7 km from Redway. 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 USC00047404 (Richardson Gr SP). Public domain.