Yoncalla climate

Yoncalla Frost Dates and Growing Season

NOAA 1991-2020 normals for Drain, 7.6 km from Yoncalla, elevation 292 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Drain. 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 16 and the first fall freeze around October 25, a growing season of about 193 days.

Median at 36°F
last May 8, first October 3
Median at 32°F
last April 16, first October 25
Median at 28°F
last March 10, 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 26May 19May 15May 12May 8May 4May 1Apr 28Apr 23
32°FMay 8May 2Apr 28Apr 22Apr 16Apr 11Apr 5Mar 31Mar 23
28°FApr 4Mar 28Mar 22Mar 16Mar 10Mar 2Feb 25Feb 16Feb 1
24°FMar 8Feb 27Feb 20Feb 14Feb 4Jan 25Jan 10Dec 30Dec 10
20°FFeb 21Feb 13Feb 1Jan 14Jan 2Dec 28Dec 20Dec 10Dec 1
16°FFeb 11Jan 7Dec 30Dec 23Dec 20Dec 16Dec 12Dec 7Nov 30

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 12Sep 21Sep 26Sep 30Oct 3Oct 7Oct 13Oct 18Oct 26
32°FOct 2Oct 9Oct 16Oct 20Oct 25Oct 30Nov 4Nov 14Nov 25
28°FOct 21Oct 29Nov 4Nov 12Nov 21Nov 29Dec 6Dec 16Dec 29
24°FNov 2Nov 14Nov 27Dec 4Dec 14Dec 22Jan 1Jan 15Feb 3
20°FNov 13Nov 30Dec 7Dec 14Dec 21Dec 28Jan 3Jan 20Feb 13
16°FNov 30Dec 5Dec 9Dec 12Dec 17Dec 21Dec 25Dec 31Feb 1

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°F176166159154148142136129120
32°F233218207199193187181172161
28°F307290278269258249239226212
24°F365356343331320311303291275
20°F365365365365365360348334315
16°F365365365365365365365365351

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
87% of years
20°F or colder
51% of years
16°F or colder
19% 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
4,300
Cooling degree days, base 65°F
339
Growing degree days, base 40°F
5,273
Growing degree days, base 45°F
3,724
Growing degree days, base 50°F
2,472
Growing degree days, base 55°F
1,514
Growing degree days, base 60°F
811

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January69306
February566013
March535037
April406190
May25211233
June12333360
July25122563
August24123564
September9745398
October3213167
November542034
December71807

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 7.6 km from Yoncalla. 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 USC00352406 (Drain). Public domain.