Hobart climate

Hobart Frost Dates and Growing Season

NOAA 1991-2020 normals for Hobart Muni AP, 5.8 km from Hobart, elevation 1556 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hobart Muni AP. 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 4 and the first fall freeze around November 4, a growing season of about 214 days.

Median at 36°F
last April 17, first October 27
Median at 32°F
last April 4, first November 4
Median at 28°F
last March 21, first November 13

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 1Apr 26Apr 22Apr 20Apr 17Apr 13Apr 9Apr 5Apr 1
32°FApr 21Apr 16Apr 12Apr 7Apr 4Mar 31Mar 27Mar 22Mar 15
28°FApr 8Apr 4Mar 31Mar 25Mar 21Mar 17Mar 12Mar 8Mar 1
24°FMar 30Mar 20Mar 15Mar 11Mar 7Mar 3Feb 28Feb 24Feb 17
20°FMar 15Mar 8Mar 4Feb 28Feb 24Feb 19Feb 14Feb 6Jan 27
16°FMar 6Feb 28Feb 21Feb 14Feb 8Jan 31Jan 26Jan 17Jan 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°FOct 14Oct 20Oct 23Oct 25Oct 27Oct 30Nov 1Nov 5Nov 9
32°FOct 22Oct 26Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 18
28°FOct 27Nov 2Nov 6Nov 10Nov 13Nov 17Nov 20Nov 25Dec 1
24°FNov 5Nov 11Nov 16Nov 20Nov 24Nov 28Dec 2Dec 5Dec 13
20°FNov 15Nov 22Nov 27Dec 1Dec 5Dec 9Dec 17Dec 22Jan 1
16°FNov 25Dec 3Dec 7Dec 14Dec 20Dec 26Jan 1Jan 10Jan 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°F215206201197193189185179173
32°F238229224219214209203198191
28°F263255248243237231226220211
24°F289278272266261256250242229
20°F322309302294289282275266256
16°F353341333324315308301294281

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
94% 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
3,406
Cooling degree days, base 65°F
2,307
Growing degree days, base 40°F
8,364
Growing degree days, base 45°F
6,850
Growing degree days, base 50°F
5,490
Growing degree days, base 55°F
4,284
Growing degree days, base 60°F
3,224

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January792015
February606142
March41510157
April19146323
May42208631
June1455904
July06111,076
August05711,035
September14317753
October14983414
November4506120
December747021

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 5.8 km from Hobart. 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 USW00093986 (Hobart Muni AP). Public domain.