Midway climate

Midway Frost Dates and Growing Season

NOAA 1991-2020 normals for Mountain Home Baxter AP, 1.9 km from Midway, elevation 928 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mountain Home Baxter AP. 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 2 and the first fall freeze around November 1, a growing season of about 212 days.

Median at 36°F
last April 15, first October 22
Median at 32°F
last April 2, first November 1
Median at 28°F
last March 20, first November 11

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 2Apr 27Apr 23Apr 18Apr 15Apr 11Apr 8Apr 4Mar 30
32°FApr 19Apr 13Apr 9Apr 5Apr 2Mar 30Mar 26Mar 21Mar 14
28°FApr 7Apr 1Mar 28Mar 24Mar 20Mar 16Mar 12Mar 7Mar 2
24°FMar 26Mar 20Mar 16Mar 11Mar 8Mar 4Mar 1Feb 25Feb 18
20°FMar 15Mar 10Mar 6Mar 3Feb 28Feb 22Feb 17Feb 12Feb 4
16°FMar 8Mar 1Feb 25Feb 19Feb 14Feb 9Feb 4Jan 30Jan 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°FOct 9Oct 14Oct 17Oct 20Oct 22Oct 25Oct 27Oct 30Nov 3
32°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 16
28°FOct 30Nov 2Nov 5Nov 8Nov 11Nov 16Nov 20Nov 25Nov 30
24°FNov 5Nov 10Nov 14Nov 19Nov 23Nov 27Dec 1Dec 6Dec 12
20°FNov 13Nov 20Nov 26Nov 30Dec 4Dec 10Dec 16Dec 22Dec 29
16°FNov 26Dec 5Dec 11Dec 19Dec 24Dec 28Jan 1Jan 6Jan 16

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°F210203198194189185181175169
32°F235227221216212208204199192
28°F261252246241235230226220212
24°F286276269263258253247241233
20°F310301294286281276270263253
16°F334325317312306301294286275

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
3,815
Cooling degree days, base 65°F
1,594
Growing degree days, base 40°F
7,390
Growing degree days, base 45°F
5,935
Growing degree days, base 50°F
4,625
Growing degree days, base 55°F
3,464
Growing degree days, base 60°F
2,454

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January870121
February668241
March4798122
April21339299
May64126528
June2307754
July0446911
August0416880
September27199623
October20947322
November495397
December788126

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 1.9 km from Midway. 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 USW00053918 (Mountain Home Baxter AP). Public domain.