Junction City climate

Junction City Frost Dates and Growing Season

NOAA 1991-2020 normals for Milford Lake, 7.7 km from Junction City, elevation 1213 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Milford Lake. 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 12 and the first fall freeze around October 26, a growing season of about 193 days.

Median at 36°F
last April 23, first October 17
Median at 32°F
last April 12, first October 26
Median at 28°F
last April 2, first November 3

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 7May 2Apr 30Apr 26Apr 23Apr 20Apr 17Apr 14Apr 8
32°FApr 29Apr 23Apr 20Apr 15Apr 12Apr 9Apr 6Apr 3Mar 29
28°FApr 19Apr 12Apr 8Apr 5Apr 2Mar 30Mar 26Mar 21Mar 15
24°FApr 8Apr 3Mar 30Mar 26Mar 22Mar 19Mar 15Mar 11Mar 4
20°FMar 31Mar 24Mar 19Mar 15Mar 11Mar 8Mar 5Mar 1Feb 24
16°FMar 21Mar 14Mar 10Mar 6Mar 3Mar 1Feb 26Feb 21Feb 14

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

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°F194188184179174171166161154
32°F214207202198193190185180174
28°F236229224219214210206200193
24°F258249243239234229224218211
20°F278269264259254250244239230
16°F299289283278273268263257249

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
5,143
Cooling degree days, base 65°F
1,414
Growing degree days, base 40°F
6,453
Growing degree days, base 45°F
5,179
Growing degree days, base 50°F
4,036
Growing degree days, base 55°F
3,030
Growing degree days, base 60°F
2,155

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10801
February89208
March657365
April35715180
May12394440
June9284724
July0436900
August2376838
September56177573
October28829253
November651250
December1,00003

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 7.7 km from Junction City. 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 USC00145306 (Milford Lake). Public domain.