Greentree climate

Greentree Frost Dates and Growing Season

NOAA 1991-2020 normals for Moorestown, 6.1 km from Greentree, elevation 45 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Moorestown. 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 12 and the first fall freeze around November 1, a growing season of about 200 days.

Median at 36°F
last April 29, first October 19
Median at 32°F
last April 12, first November 1
Median at 28°F
last March 29, first November 12

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 16May 9May 5May 2Apr 29Apr 25Apr 21Apr 17Apr 10
32°FMay 3Apr 27Apr 21Apr 17Apr 12Apr 8Apr 5Apr 1Mar 28
28°FApr 16Apr 7Apr 3Mar 31Mar 29Mar 25Mar 21Mar 18Mar 13
24°FMar 31Mar 26Mar 22Mar 19Mar 16Mar 13Mar 9Mar 4Feb 27
20°FMar 21Mar 16Mar 13Mar 9Mar 5Mar 1Feb 26Feb 21Feb 12
16°FMar 11Mar 5Feb 28Feb 24Feb 19Feb 13Feb 8Feb 3Jan 27

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°FOct 5Oct 10Oct 13Oct 16Oct 19Oct 22Oct 26Oct 30Nov 2
32°FOct 17Oct 22Oct 26Oct 29Nov 1Nov 3Nov 6Nov 9Nov 14
28°FOct 31Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 23Nov 30
24°FNov 8Nov 13Nov 17Nov 21Nov 24Nov 28Dec 2Dec 6Dec 15
20°FNov 21Nov 28Dec 2Dec 6Dec 11Dec 16Dec 21Dec 28Jan 4
16°FDec 7Dec 14Dec 22Dec 28Jan 1Jan 4Jan 9Jan 15Jan 24

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°F197188182177172167162157149
32°F223215210205200195190184174
28°F250244238233228224219213205
24°F279270264258253248243238230
20°F307298291285280274268261253
16°F335328321314309304300293285

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
98% 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
4,521
Cooling degree days, base 65°F
1,205
Growing degree days, base 40°F
6,400
Growing degree days, base 45°F
5,053
Growing degree days, base 50°F
3,860
Growing degree days, base 55°F
2,825
Growing degree days, base 60°F
1,935

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January95308
February79207
March655146
April33019186
May12474417
June14240676
July0384849
August1307770
September35156572
October25622251
November544165
December817013

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 6.1 km from Greentree. 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 USC00285728 (Moorestown). Public domain.