Osino climate

Osino Frost Dates and Growing Season

NOAA 1991-2020 normals for Ryndon, 5.9 km from Osino, elevation 5288 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ryndon. 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 June 7 and the first fall freeze around September 12, a growing season of about 98 days.

Median at 36°F
last June 18, first September 2
Median at 32°F
last June 7, first September 12
Median at 28°F
last May 20, first September 23

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°FJul 1Jun 27Jun 24Jun 21Jun 18Jun 16Jun 12Jun 9Jun 4
32°FJun 22Jun 17Jun 13Jun 10Jun 7Jun 3May 30May 25May 18
28°FJun 11Jun 6Jun 1May 25May 20May 15May 11May 7May 1
24°FMay 28May 18May 12May 8May 4May 1Apr 27Apr 22Apr 15
20°FMay 8May 1Apr 27Apr 22Apr 17Apr 12Apr 7Apr 2Mar 27
16°FApr 22Apr 11Apr 6Apr 1Mar 29Mar 22Mar 16Mar 9Mar 3

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°FAug 14Aug 22Aug 26Aug 30Sep 2Sep 5Sep 7Sep 10Sep 14
32°FAug 31Sep 4Sep 7Sep 10Sep 12Sep 15Sep 18Sep 21Sep 25
28°FSep 9Sep 14Sep 18Sep 20Sep 23Sep 26Sep 29Oct 2Oct 6
24°FSep 19Sep 24Sep 28Oct 1Oct 3Oct 6Oct 9Oct 14Oct 19
20°FSep 29Oct 3Oct 6Oct 10Oct 14Oct 18Oct 21Oct 25Nov 1
16°FOct 8Oct 15Oct 19Oct 23Oct 26Oct 30Nov 2Nov 6Nov 12

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°F948884807772686255
32°F1211131071029895908579
28°F14914113512912411911410799
24°F176167161156151146140133122
20°F208198192186181175169163153
16°F242231224217212205199191182

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
100% of years
16°F or colder
100% 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
7,068
Cooling degree days, base 65°F
448
Growing degree days, base 40°F
4,105
Growing degree days, base 45°F
3,057
Growing degree days, base 50°F
2,188
Growing degree days, base 55°F
1,471
Growing degree days, base 60°F
886

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25200
February97400
March82503
April599137
May3685158
June13251378
July9220676
August30151586
September19820293
October561055
November91102
December1,20900

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 5.9 km from Osino. 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 USC00267188 (Ryndon). Public domain.