Walker climate

Walker Frost Dates and Growing Season

NOAA 1991-2020 normals for E Grand Rapids, 14.4 km from Walker, elevation 746 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for E Grand Rapids. 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 6 and the first fall freeze around October 10, a growing season of about 157 days.

Median at 36°F
last May 18, first October 1
Median at 32°F
last May 6, first October 10
Median at 28°F
last April 27, first October 23

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 31May 27May 24May 21May 18May 15May 11May 7May 3
32°FMay 23May 17May 14May 9May 6May 4May 1Apr 28Apr 24
28°FMay 13May 6May 2Apr 30Apr 27Apr 24Apr 20Apr 17Apr 11
24°FMay 1Apr 26Apr 21Apr 18Apr 15Apr 11Apr 8Apr 5Mar 31
20°FApr 19Apr 14Apr 9Apr 6Apr 3Apr 1Mar 29Mar 25Mar 18
16°FApr 7Apr 2Mar 31Mar 28Mar 24Mar 20Mar 18Mar 14Mar 7

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 20Sep 25Sep 27Sep 30Oct 1Oct 4Oct 6Oct 9Oct 12
32°FSep 29Oct 2Oct 5Oct 7Oct 10Oct 13Oct 15Oct 19Oct 25
28°FOct 8Oct 13Oct 16Oct 19Oct 23Oct 26Oct 30Nov 2Nov 7
24°FOct 21Oct 26Oct 30Nov 2Nov 5Nov 8Nov 12Nov 16Nov 23
20°FNov 3Nov 8Nov 13Nov 17Nov 20Nov 24Nov 28Dec 2Dec 8
16°FNov 14Nov 21Nov 26Nov 30Dec 2Dec 5Dec 10Dec 16Dec 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°F155148144140136132128124117
32°F176169165161157153149144138
28°F199192187183178174170165158
24°F226218212208203199195190182
20°F254246240235230226221215208
16°F277269264258253248244239231

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
6,712
Cooling degree days, base 65°F
547
Growing degree days, base 40°F
4,596
Growing degree days, base 45°F
3,532
Growing degree days, base 50°F
2,590
Growing degree days, base 55°F
1,774
Growing degree days, base 60°F
1,085

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,27800
February1,09700
March95303
April574361
May25120255
June43114521
July7199657
August20156601
September13750367
October4585109
November789016
December1,10501

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 14.4 km from Walker. 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 USC00202375 (E Grand Rapids). Public domain.