Troy climate

Troy Frost Dates and Growing Season

NOAA 1991-2020 normals for Troy 3N, 5 km from Troy, elevation 1040 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Troy 3N. 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 19 and the first fall freeze around October 19, a growing season of about 182 days.

Median at 36°F
last April 29, first October 8
Median at 32°F
last April 19, first October 19
Median at 28°F
last April 8, first October 29

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 12May 7May 4May 1Apr 29Apr 25Apr 22Apr 19Apr 14
32°FMay 5Apr 30Apr 25Apr 22Apr 19Apr 16Apr 12Apr 9Apr 4
28°FApr 25Apr 19Apr 15Apr 11Apr 8Apr 5Apr 2Mar 30Mar 23
24°FApr 13Apr 7Apr 4Apr 1Mar 30Mar 26Mar 22Mar 17Mar 11
20°FApr 2Mar 29Mar 25Mar 22Mar 18Mar 14Mar 10Mar 6Feb 28
16°FMar 25Mar 19Mar 15Mar 11Mar 8Mar 5Mar 2Feb 27Feb 21

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 28Oct 2Oct 5Oct 8Oct 11Oct 14Oct 18Oct 23
32°FOct 2Oct 9Oct 13Oct 16Oct 19Oct 22Oct 25Oct 28Nov 1
28°FOct 13Oct 19Oct 23Oct 26Oct 29Oct 31Nov 2Nov 5Nov 10
24°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 23
20°FNov 1Nov 4Nov 8Nov 12Nov 16Nov 20Nov 23Nov 28Dec 4
16°FNov 7Nov 13Nov 17Nov 22Nov 26Nov 29Dec 3Dec 8Dec 15

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°F183175170166162158153148142
32°F203195190185182177172166160
28°F223215210206202198194189179
24°F247237231227222217213207200
20°F268258252247243237232227219
16°F284277271265261256250245237

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
5,493
Cooling degree days, base 65°F
1,200
Growing degree days, base 40°F
6,115
Growing degree days, base 45°F
4,870
Growing degree days, base 50°F
3,760
Growing degree days, base 55°F
2,775
Growing degree days, base 60°F
1,920

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19301
February94608
March702359
April37113173
May12987429
June12250688
July2369832
August4313773
September70139521
October32325229
November686144
December1,05403

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 km from Troy. 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 USC00148250 (Troy 3N). Public domain.