Kellogg climate

Kellogg Frost Dates and Growing Season

NOAA 1991-2020 normals for Newton, 10.2 km from Kellogg, elevation 960 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newton. 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 22 and the first fall freeze around October 17, a growing season of about 174 days.

Median at 36°F
last May 2, first October 4
Median at 32°F
last April 22, first October 17
Median at 28°F
last April 12, first October 26

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 13May 9May 6May 4May 2Apr 30Apr 27Apr 23Apr 19
32°FMay 4May 1Apr 28Apr 25Apr 22Apr 19Apr 16Apr 13Apr 8
28°FApr 25Apr 20Apr 17Apr 14Apr 12Apr 9Apr 6Apr 3Mar 30
24°FApr 18Apr 12Apr 8Apr 6Apr 3Apr 1Mar 29Mar 24Mar 19
20°FApr 11Apr 5Apr 2Mar 31Mar 27Mar 23Mar 19Mar 16Mar 9
16°FApr 1Mar 29Mar 24Mar 20Mar 17Mar 13Mar 10Mar 6Mar 2

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 21Sep 27Sep 29Oct 1Oct 4Oct 7Oct 10Oct 14Oct 18
32°FOct 1Oct 6Oct 11Oct 13Oct 17Oct 19Oct 22Oct 25Oct 28
28°FOct 14Oct 18Oct 21Oct 24Oct 26Oct 29Oct 31Nov 2Nov 6
24°FOct 22Oct 27Oct 30Nov 1Nov 3Nov 5Nov 8Nov 11Nov 16
20°FOct 31Nov 2Nov 5Nov 8Nov 11Nov 14Nov 17Nov 21Nov 28
16°FNov 5Nov 10Nov 13Nov 16Nov 20Nov 24Nov 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°F172166162158156152148144139
32°F193187182178174171167164157
28°F213206202198194191187182176
24°F232225220216211208205200193
20°F252244238234229226222217210
16°F270261256252247243238232225

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
6,803
Cooling degree days, base 65°F
862
Growing degree days, base 40°F
5,209
Growing degree days, base 45°F
4,104
Growing degree days, base 50°F
3,112
Growing degree days, base 55°F
2,238
Growing degree days, base 60°F
1,485

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,42000
February1,15601
March897123
April4924100
May19054343
June23191618
July3288750
August10225680
September11089433
October43111147
November840017
December1,23201

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 10.2 km from Kellogg. 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 USC00135992 (Newton). Public domain.