Junction climate

Junction Frost Dates and Growing Season

NOAA 1991-2020 normals for Circleville, 9.1 km from Junction, elevation 6050 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Circleville. 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 23 and the first fall freeze around September 27, a growing season of about 125 days.

Median at 36°F
last June 5, first September 20
Median at 32°F
last May 23, first September 27
Median at 28°F
last May 8, first October 5

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 22Jun 16Jun 12Jun 8Jun 5Jun 2May 30May 26May 20
32°FJun 13Jun 6Jun 1May 28May 23May 19May 15May 10May 4
28°FJun 3May 24May 17May 13May 8May 3Apr 30Apr 26Apr 20
24°FMay 17May 7May 2Apr 29Apr 25Apr 21Apr 16Apr 12Apr 7
20°FMay 1Apr 25Apr 19Apr 13Apr 10Apr 6Apr 3Mar 30Mar 22
16°FApr 12Apr 6Apr 1Mar 28Mar 23Mar 17Mar 11Mar 5Feb 27

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 4Sep 8Sep 13Sep 16Sep 20Sep 23Sep 25Sep 27Oct 1
32°FSep 12Sep 17Sep 21Sep 25Sep 27Sep 30Oct 1Oct 4Oct 8
28°FSep 22Sep 26Sep 30Oct 2Oct 5Oct 8Oct 12Oct 16Oct 19
24°FSep 29Oct 4Oct 8Oct 12Oct 16Oct 18Oct 21Oct 25Oct 31
20°FOct 7Oct 14Oct 19Oct 23Oct 26Oct 30Nov 2Nov 6Nov 11
16°FOct 20Oct 27Oct 31Nov 4Nov 7Nov 10Nov 13Nov 18Nov 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°F12411711110710298948982
32°F14914113513012512111510898
28°F172164159154149143137131119
24°F196188182177172167161154145
20°F224215208202197192187181172
16°F258248240234228222215209199

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
5,964
Cooling degree days, base 65°F
538
Growing degree days, base 40°F
4,726
Growing degree days, base 45°F
3,555
Growing degree days, base 50°F
2,565
Growing degree days, base 55°F
1,734
Growing degree days, base 60°F
1,063

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07400
February84700
March721010
April504067
May27310225
June7495472
July4227688
August7168626
September11838375
October459193
November78208
December1,10200

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 9.1 km from Junction. 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 USC00421432 (Circleville). Public domain.