Manassa climate

Manassa Frost Dates and Growing Season

NOAA 1991-2020 normals for Manassa, 0.4 km from Manassa, elevation 7695 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Manassa. 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 28 and the first fall freeze around September 21, a growing season of about 115 days.

Median at 36°F
last June 10, first September 11
Median at 32°F
last May 28, first September 21
Median at 28°F
last May 13, first September 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°FJun 26Jun 20Jun 16Jun 12Jun 10Jun 7Jun 3May 31May 27
32°FJun 11Jun 6Jun 2May 31May 28May 24May 21May 17May 13
28°FJun 2May 26May 20May 17May 13May 10May 7May 4Apr 30
24°FMay 16May 10May 7May 4May 1Apr 30Apr 27Apr 24Apr 19
20°FMay 5May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 12Apr 7
16°FApr 28Apr 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 2Mar 26

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 30Sep 2Sep 6Sep 8Sep 11Sep 13Sep 15Sep 18Sep 23
32°FSep 9Sep 14Sep 17Sep 19Sep 21Sep 23Sep 25Sep 28Oct 1
28°FSep 18Sep 22Sep 25Sep 27Sep 29Oct 1Oct 2Oct 5Oct 9
24°FSep 26Sep 30Oct 2Oct 4Oct 6Oct 9Oct 12Oct 15Oct 19
20°FOct 2Oct 5Oct 9Oct 12Oct 15Oct 18Oct 21Oct 24Oct 29
16°FOct 9Oct 14Oct 18Oct 21Oct 24Oct 28Oct 31Nov 3Nov 7

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°F10910399959287847973
32°F13312712211811511110810397
28°F154148144140137133128124117
24°F174169163159156152149145139
20°F194188183179174171166161156
16°F217208203198194190185181173

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
7,776
Cooling degree days, base 65°F
71
Growing degree days, base 40°F
3,462
Growing degree days, base 45°F
2,447
Growing degree days, base 50°F
1,589
Growing degree days, base 55°F
890
Growing degree days, base 60°F
366

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,39700
February1,06700
March87601
April626020
May3791131
June12514340
July4239462
August8116400
September2561205
October600029
November96301
December1,36600

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 0.4 km from Manassa. 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 USC00055322 (Manassa). Public domain.