Plattsburgh climate

Plattsburgh Frost Dates and Growing Season

NOAA 1991-2020 normals for Plattsburgh Intl AP, 5.7 km from Plattsburgh, elevation 234 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Plattsburgh Intl 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 May 6 and the first fall freeze around October 5, a growing season of about 152 days.

Median at 36°F
last May 19, first September 24
Median at 32°F
last May 6, first October 5
Median at 28°F
last April 25, first October 19

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 3May 29May 25May 22May 19May 16May 14May 10May 5
32°FMay 19May 15May 11May 8May 6May 3May 1Apr 28Apr 24
28°FMay 8May 3Apr 30Apr 27Apr 25Apr 22Apr 20Apr 16Apr 12
24°FApr 25Apr 21Apr 17Apr 15Apr 12Apr 10Apr 8Apr 6Apr 3
20°FApr 16Apr 11Apr 8Apr 6Apr 4Apr 2Mar 31Mar 28Mar 22
16°FApr 7Apr 4Apr 2Mar 31Mar 29Mar 26Mar 23Mar 19Mar 15

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 13Sep 16Sep 19Sep 22Sep 24Sep 27Sep 30Oct 2Oct 7
32°FSep 23Sep 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 16Oct 22
28°FOct 3Oct 8Oct 12Oct 16Oct 19Oct 22Oct 26Oct 31Nov 3
24°FOct 15Oct 22Oct 26Oct 31Nov 2Nov 4Nov 7Nov 11Nov 14
20°FOct 31Nov 3Nov 5Nov 9Nov 12Nov 14Nov 17Nov 21Nov 26
16°FNov 7Nov 12Nov 15Nov 18Nov 21Nov 23Nov 27Dec 1Dec 4

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°F145140135131127124120116109
32°F170163159155152148144139134
28°F196189185181177173167163155
24°F220214209205201197193188181
20°F238232227224220217213208202
16°F255248244239236232229225219

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
7,546
Cooling degree days, base 65°F
392
Growing degree days, base 40°F
4,139
Growing degree days, base 45°F
3,116
Growing degree days, base 50°F
2,230
Growing degree days, base 55°F
1,468
Growing degree days, base 60°F
846

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,42300
February1,23200
March1,07704
April646136
May29113213
June8466433
July12164617
August29113549
September19435300
October528171
November83308
December1,19800

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 5.7 km from Plattsburgh. 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 USW00064776 (Plattsburgh Intl AP). Public domain.