Tomahawk climate

Tomahawk Frost Dates and Growing Season

NOAA 1991-2020 normals for Rice Rsvr Tomahawk-2, 7.4 km from Tomahawk, elevation 1460 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rice Rsvr Tomahawk-2. 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 10 and the first fall freeze around October 4, a growing season of about 146 days.

Median at 36°F
last May 23, first September 25
Median at 32°F
last May 10, first October 4
Median at 28°F
last April 30, first October 16

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 5Jun 1May 30May 26May 23May 21May 17May 14May 8
32°FMay 27May 21May 17May 13May 10May 8May 5May 1Apr 28
28°FMay 13May 9May 5May 2Apr 30Apr 28Apr 25Apr 22Apr 15
24°FMay 3Apr 30Apr 27Apr 24Apr 21Apr 18Apr 15Apr 11Apr 6
20°FApr 26Apr 21Apr 18Apr 14Apr 12Apr 9Apr 7Apr 3Mar 31
16°FApr 19Apr 15Apr 11Apr 8Apr 5Apr 3Apr 1Mar 29Mar 24

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 11Sep 17Sep 20Sep 23Sep 25Sep 28Oct 1Oct 3Oct 7
32°FSep 21Sep 26Sep 29Oct 1Oct 4Oct 6Oct 9Oct 13Oct 18
28°FSep 30Oct 5Oct 9Oct 12Oct 16Oct 19Oct 23Oct 27Nov 1
24°FOct 14Oct 19Oct 23Oct 26Oct 30Nov 1Nov 3Nov 6Nov 11
20°FOct 26Oct 31Nov 1Nov 4Nov 7Nov 10Nov 12Nov 16Nov 20
16°FNov 1Nov 5Nov 8Nov 11Nov 15Nov 17Nov 20Nov 24Nov 28

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°F144137132128125121116111104
32°F165158153149146142137132126
28°F187180175170166162157152147
24°F210203197193188185180175169
20°F228222217212208204200195188
16°F241235230226222218215210204

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
9,051
Cooling degree days, base 65°F
251
Growing degree days, base 40°F
3,571
Growing degree days, base 45°F
2,654
Growing degree days, base 50°F
1,853
Growing degree days, base 55°F
1,170
Growing degree days, base 60°F
624

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,66300
February1,41500
March1,21705
April767021
May37510167
June11550388
July46103522
August7165459
September25921240
October642150
November1,03202
December1,45100

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 7.4 km from Tomahawk. 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 USC00477142 (Rice Rsvr Tomahawk-2). Public domain.