Midway climate

Midway Frost Dates and Growing Season

NOAA 1991-2020 normals for Heber, 4.6 km from Midway, elevation 5590 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Heber. 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 4 and the first fall freeze around September 20, a growing season of about 106 days.

Median at 36°F
last June 19, first September 9
Median at 32°F
last June 4, first September 20
Median at 28°F
last May 17, first October 1

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 2Jun 28Jun 25Jun 23Jun 19Jun 16Jun 13Jun 9Jun 5
32°FJun 21Jun 15Jun 11Jun 7Jun 4May 31May 28May 23May 18
28°FJun 8Jun 1May 28May 21May 17May 13May 9May 5May 1
24°FMay 17May 11May 7May 2Apr 29Apr 26Apr 21Apr 17Apr 12
20°FApr 29Apr 22Apr 18Apr 14Apr 11Apr 6Apr 3Mar 31Mar 23
16°FApr 10Apr 5Mar 31Mar 27Mar 22Mar 17Mar 13Mar 9Mar 4

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 28Sep 1Sep 4Sep 7Sep 9Sep 12Sep 14Sep 18Sep 21
32°FSep 6Sep 11Sep 14Sep 17Sep 20Sep 22Sep 24Sep 27Oct 1
28°FSep 17Sep 22Sep 25Sep 28Oct 1Oct 3Oct 5Oct 9Oct 15
24°FSep 29Oct 3Oct 6Oct 10Oct 13Oct 17Oct 21Oct 25Oct 31
20°FOct 10Oct 16Oct 21Oct 24Oct 27Oct 31Nov 2Nov 6Nov 11
16°FOct 23Oct 28Nov 1Nov 3Nov 6Nov 10Nov 14Nov 17Nov 22

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°F999389848075716658
32°F128120115110106102989385
28°F157149143138134129123116107
24°F190182177172167162158152144
20°F222213207202198194190183176
16°F252243236231227222216210202

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
6,999
Cooling degree days, base 65°F
307
Growing degree days, base 40°F
4,038
Growing degree days, base 45°F
2,967
Growing degree days, base 50°F
2,061
Growing degree days, base 55°F
1,316
Growing degree days, base 60°F
729

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25500
February1,02100
March82903
April580033
May3522155
June12429358
July11152606
August20113558
September18112287
October524058
November87903
December1,22300

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 4.6 km from Midway. 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 USC00423809 (Heber). Public domain.