Tower City climate

Tower City Frost Dates and Growing Season

NOAA 1991-2020 normals for Dehart Dam, 21.9 km from Tower City, elevation 537 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dehart Dam. 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 1 and the first fall freeze around October 16, a growing season of about 168 days.

Median at 36°F
last May 12, first October 5
Median at 32°F
last May 1, first October 16
Median at 28°F
last April 18, first October 30

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 27May 23May 19May 15May 12May 8May 4Apr 30Apr 26
32°FMay 20May 14May 9May 5May 1Apr 28Apr 24Apr 20Apr 15
28°FMay 8May 1Apr 25Apr 20Apr 18Apr 14Apr 10Apr 5Apr 1
24°FApr 19Apr 12Apr 7Apr 4Apr 1Mar 30Mar 28Mar 23Mar 17
20°FApr 2Mar 30Mar 26Mar 23Mar 19Mar 16Mar 13Mar 9Mar 3
16°FMar 24Mar 19Mar 15Mar 13Mar 10Mar 6Mar 3Feb 28Feb 22

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 23Sep 27Sep 30Oct 3Oct 5Oct 7Oct 10Oct 13Oct 18
32°FOct 3Oct 6Oct 10Oct 13Oct 16Oct 19Oct 23Oct 28Nov 1
28°FOct 10Oct 17Oct 22Oct 26Oct 30Nov 1Nov 4Nov 8Nov 13
24°FOct 26Nov 1Nov 4Nov 8Nov 11Nov 14Nov 17Nov 22Nov 30
20°FNov 9Nov 14Nov 18Nov 22Nov 26Nov 30Dec 3Dec 8Dec 15
16°FNov 20Nov 28Dec 2Dec 5Dec 9Dec 13Dec 17Dec 23Dec 30

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°F166159154150145141137133127
32°F190183178173168165159154145
28°F218210204199194189184178169
24°F245238233228223219214208200
20°F275267260254249245240235227
16°F301292286281275270265259251

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
5,861
Cooling degree days, base 65°F
642
Growing degree days, base 40°F
5,053
Growing degree days, base 45°F
3,872
Growing degree days, base 50°F
2,845
Growing degree days, base 55°F
1,962
Growing degree days, base 60°F
1,225

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13301
February97402
March835017
April479598
May21633294
June44126533
July6220679
August12183637
September10268418
October3976142
November681023
December98103

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 21.9 km from Tower 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 USC00362071 (Dehart Dam). Public domain.