Canyonville climate

Canyonville Frost Dates and Growing Season

NOAA 1991-2020 normals for Riddle, 6.7 km from Canyonville, elevation 680 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Riddle. 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 31 and the first fall freeze around November 6, a growing season of about 221 days.

Median at 36°F
last April 27, first October 14
Median at 32°F
last March 31, first November 6
Median at 28°F
last February 20, first December 10

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 14May 9May 4Apr 30Apr 27Apr 23Apr 20Apr 14Apr 8
32°FApr 27Apr 18Apr 11Apr 5Mar 31Mar 26Mar 20Mar 10Feb 27
28°FMar 31Mar 18Mar 7Feb 28Feb 20Feb 14Feb 1Jan 14Dec 22
24°FFeb 24Feb 15Feb 1Jan 17Jan 6Dec 30Dec 16Dec 7Nov 19
20°FJan 15Dec 31Dec 29Dec 23Dec 15Dec 12Dec 9Nov 30Nov 10
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°FSep 28Oct 1Oct 6Oct 10Oct 14Oct 18Oct 24Oct 30Nov 7
32°FOct 11Oct 20Oct 26Oct 31Nov 6Nov 15Nov 25Dec 4Dec 13
28°FOct 28Nov 7Nov 19Dec 2Dec 10Dec 22Jan 1Jan 15Feb 12
24°FNov 3Nov 19Dec 1Dec 10Dec 21Dec 29Jan 10Jan 30Feb 17
20°FNov 10Nov 30Dec 7Dec 10Dec 12Dec 20Dec 26Dec 31Jan 13
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°F204192184178172167161155145
32°F266250240231221212204195184
28°F353328314303292282268252234
24°F365365365365364349335319304
20°F365365365365365365365365347
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
100% of years
28°F or colder
93% of years
24°F or colder
48% of years
20°F or colder
15% of years
16°F or colder
6% 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
3,630
Cooling degree days, base 65°F
628
Growing degree days, base 40°F
6,171
Growing degree days, base 45°F
4,531
Growing degree days, base 50°F
3,153
Growing degree days, base 55°F
2,067
Growing degree days, base 60°F
1,233

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January626012
February500030
March460073
April3393141
May17927316
June6675459
July7216674
August8206663
September5990482
October25310233
November471058
December662012

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 6.7 km from Canyonville. 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 USC00357169 (Riddle). Public domain.