Quincy climate

Quincy Frost Dates and Growing Season

NOAA 1991-2020 normals for Quincy, 0.1 km from Quincy, elevation 3420 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Quincy. 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 September 25, a growing season of about 122 days.

Median at 32°F
last May 22, first September 25
Median at 28°F
last April 29, first October 9

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°F–––––––––
32°FJun 14Jun 7Jun 1May 27May 22May 18May 14May 8May 3
28°FMay 21May 12May 5May 1Apr 29Apr 26Apr 23Apr 20Apr 15
24°FApr 28Apr 22Apr 18Apr 15Apr 12Apr 7Apr 3Mar 29Mar 20
20°FApr 10Apr 1Mar 23Mar 15Mar 9Mar 4Feb 28Feb 22Feb 10
16°FMar 8Mar 1Feb 25Feb 19Feb 13Feb 4Jan 26Jan 12Dec 29

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°F–––––––––
32°FSep 4Sep 11Sep 16Sep 20Sep 25Sep 28Oct 1Oct 4Oct 9
28°FSep 25Sep 30Oct 3Oct 6Oct 9Oct 13Oct 16Oct 21Oct 27
24°FOct 8Oct 15Oct 20Oct 24Oct 29Nov 1Nov 4Nov 10Nov 17
20°FOct 24Oct 31Nov 4Nov 9Nov 14Nov 19Nov 23Nov 28Dec 5
16°FNov 8Nov 16Nov 20Nov 25Dec 1Dec 5Dec 11Dec 19Jan 3

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°F1069790857973675950
32°F14714013412812211711110596
28°F186178173168163159154148139
24°F228218211205200195190183175
20°F287272261254248240233225211
16°F337324313304294284276267256

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
97% 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
5,728
Cooling degree days, base 65°F
283
Growing degree days, base 40°F
4,276
Growing degree days, base 45°F
3,077
Growing degree days, base 50°F
2,100
Growing degree days, base 55°F
1,323
Growing degree days, base 60°F
709

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January94400
February75601
March69406
April536038
May3287177
June13537357
July25129569
August3787515
September13922337
October440197
November74004
December95500

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 0.1 km from Quincy. 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 USC00047195 (Quincy). Public domain.