Franklin climate

Franklin Frost Dates and Growing Season

NOAA 1991-2020 normals for Franklin Sewage Plt, 1.9 km from Franklin, elevation 655 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Franklin Sewage Plt. 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 3 and the first fall freeze around October 31, a growing season of about 210 days.

Median at 36°F
last April 16, first October 22
Median at 32°F
last April 3, first October 31
Median at 28°F
last March 22, first November 10

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 2Apr 29Apr 24Apr 20Apr 16Apr 12Apr 9Apr 5Mar 31
32°FApr 20Apr 14Apr 10Apr 7Apr 3Mar 31Mar 27Mar 22Mar 17
28°FApr 8Apr 2Mar 30Mar 26Mar 22Mar 18Mar 15Mar 10Mar 2
24°FMar 27Mar 20Mar 16Mar 12Mar 8Mar 4Feb 28Feb 24Feb 15
20°FMar 16Mar 8Mar 3Feb 28Feb 24Feb 18Feb 12Feb 5Jan 30
16°FMar 7Feb 28Feb 20Feb 13Feb 7Feb 3Jan 31Jan 24Jan 13

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 10Oct 14Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30Nov 3
32°FOct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 8Nov 13
28°FOct 30Nov 1Nov 4Nov 7Nov 10Nov 14Nov 17Nov 23Nov 30
24°FNov 6Nov 11Nov 15Nov 19Nov 24Nov 29Dec 1Dec 6Dec 17
20°FNov 15Nov 25Nov 30Dec 3Dec 8Dec 13Dec 21Dec 27Jan 4
16°FDec 1Dec 8Dec 17Dec 24Dec 29Jan 1Jan 7Jan 13Jan 23

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°F209202196191187183179174166
32°F233224218214210206203198190
28°F258250244238233229223218210
24°F288278272265259253248242234
20°F321310302295289282275268258
16°F356339332325318310304297285

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
95% 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
3,601
Cooling degree days, base 65°F
1,686
Growing degree days, base 40°F
7,602
Growing degree days, base 45°F
6,113
Growing degree days, base 50°F
4,769
Growing degree days, base 55°F
3,581
Growing degree days, base 60°F
2,554

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January811030
February638140
March4727124
April21840296
May64140541
June3327774
July0454919
August0420885
September20239669
October19252342
November4745107
December709142

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 1.9 km from Franklin. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00403280 (Franklin Sewage Plt). Public domain.