Mio climate

Mio Frost Dates and Growing Season

NOAA 1991-2020 normals for Mio Wwtp, 1.3 km from Mio, elevation 1037 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mio Wwtp. 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 May 20 and the first fall freeze around October 1, a growing season of about 133 days.

Median at 36°F
last June 2, first September 19
Median at 32°F
last May 20, first October 1
Median at 28°F
last May 5, first October 14

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°FJun 20Jun 14Jun 8Jun 5Jun 2May 31May 28May 24May 17
32°FJun 2May 30May 27May 23May 20May 16May 12May 7May 2
28°FMay 23May 18May 13May 8May 5May 1Apr 29Apr 27Apr 22
24°FMay 11May 5Apr 30Apr 27Apr 25Apr 22Apr 19Apr 16Apr 10
20°FApr 29Apr 22Apr 19Apr 16Apr 13Apr 9Apr 7Apr 4Mar 31
16°FApr 17Apr 12Apr 8Apr 5Apr 3Apr 1Mar 30Mar 26Mar 21

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 3Sep 9Sep 13Sep 16Sep 19Sep 21Sep 24Sep 27Oct 1
32°FSep 16Sep 22Sep 25Sep 28Oct 1Oct 3Oct 5Oct 8Oct 14
28°FOct 1Oct 4Oct 8Oct 11Oct 14Oct 17Oct 19Oct 23Oct 29
24°FOct 14Oct 18Oct 21Oct 24Oct 27Oct 31Nov 2Nov 6Nov 11
20°FOct 26Oct 30Nov 2Nov 5Nov 9Nov 11Nov 15Nov 20Nov 25
16°FNov 5Nov 10Nov 14Nov 18Nov 22Nov 25Nov 28Dec 1Dec 7

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°F127120115110106102979183
32°F154147141137133129124119112
28°F179173167163158154149144138
24°F203197192187183179175170164
20°F229222217212207203198193186
16°F252244240235232227223218210

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
7,833
Cooling degree days, base 65°F
383
Growing degree days, base 40°F
3,942
Growing degree days, base 45°F
2,967
Growing degree days, base 50°F
2,123
Growing degree days, base 55°F
1,398
Growing degree days, base 60°F
806

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,41500
February1,23600
March1,09018
April698137
May33921205
June10379429
July40141566
August56101510
September21136291
October562270
November86909
December1,21400

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 1.3 km from Mio. 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 USC00205533 (Mio Wwtp). Public domain.