Pittman Center climate

Pittman Center Frost Dates and Growing Season

NOAA 1991-2020 normals for Mt Leconte, 12.3 km from Pittman Center, elevation 6493 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mt Leconte. 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 22 and the first fall freeze around October 1, a growing season of about 132 days.

Median at 36°F
last June 4, first September 16
Median at 32°F
last May 22, first October 1
Median at 28°F
last May 9, first October 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°FJun 29Jun 20Jun 14Jun 8Jun 4Jun 1May 28May 23May 16
32°FJun 11Jun 2May 30May 26May 22May 17May 14May 11May 7
28°FMay 26May 20May 15May 12May 9May 7May 5May 1Apr 26
24°FMay 16May 10May 6May 4May 1Apr 28Apr 24Apr 20Apr 15
20°FMay 7May 2Apr 29Apr 24Apr 21Apr 16Apr 13Apr 9Apr 4
16°FApr 29Apr 23Apr 16Apr 12Apr 9Apr 5Apr 2Mar 29Mar 20

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°FAug 23Sep 2Sep 7Sep 12Sep 16Sep 20Sep 23Sep 27Oct 3
32°FSep 15Sep 20Sep 24Sep 28Oct 1Oct 4Oct 7Oct 10Oct 15
28°FSep 26Oct 1Oct 4Oct 7Oct 10Oct 12Oct 15Oct 19Oct 24
24°FOct 5Oct 10Oct 13Oct 16Oct 19Oct 22Oct 25Oct 28Oct 31
20°FOct 12Oct 17Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 10
16°FOct 20Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 13Nov 19

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°F12811911310710196908269
32°F153146141136132126121115105
28°F173165160156152149145140132
24°F192185179174170166162156149
20°F213204199194189185179174167
16°F235226219214210205200193183

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
8,301
Cooling degree days, base 65°F
1
Growing degree days, base 40°F
2,610
Growing degree days, base 45°F
1,631
Growing degree days, base 50°F
841
Growing degree days, base 55°F
289
Growing degree days, base 60°F
38

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,22400
February1,05400
March1,00601
April722015
May518060
June3060159
July2191248
August2440224
September3740110
October631024
November89401
December1,11000

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 12.3 km from Pittman Center. 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 USC00406328 (Mt Leconte). Public domain.