Newtown Grant climate

Newtown Grant Frost Dates and Growing Season

NOAA 1991-2020 normals for Lambertville, 11.1 km from Newtown Grant, elevation 68 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lambertville. 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 16 and the first fall freeze around October 19, a growing season of about 185 days.

Median at 36°F
last April 29, first October 8
Median at 32°F
last April 16, first October 19
Median at 28°F
last April 3, first November 1

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 14May 9May 4May 1Apr 29Apr 27Apr 24Apr 21Apr 17
32°FApr 30Apr 25Apr 21Apr 18Apr 16Apr 14Apr 10Apr 7Apr 2
28°FApr 17Apr 12Apr 8Apr 5Apr 3Mar 31Mar 30Mar 26Mar 21
24°FApr 5Apr 2Mar 30Mar 27Mar 24Mar 21Mar 18Mar 14Mar 8
20°FMar 28Mar 23Mar 19Mar 16Mar 13Mar 9Mar 6Mar 2Feb 26
16°FMar 19Mar 14Mar 9Mar 5Mar 3Feb 28Feb 24Feb 16Feb 5

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 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 19Oct 26
32°FOct 4Oct 8Oct 12Oct 16Oct 19Oct 23Oct 27Nov 1Nov 4
28°FOct 12Oct 18Oct 23Oct 27Nov 1Nov 3Nov 6Nov 10Nov 14
24°FOct 23Oct 30Nov 4Nov 8Nov 11Nov 14Nov 18Nov 22Nov 27
20°FNov 7Nov 14Nov 18Nov 21Nov 25Nov 29Dec 2Dec 6Dec 13
16°FNov 24Nov 30Dec 3Dec 7Dec 11Dec 16Dec 21Dec 26Jan 2

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°F183176171167164159155150143
32°F207199194190185180176171165
28°F231223217213208204199194186
24°F255247242237232228224217209
20°F281273267262257253248243234
16°F312303295289283279274268259

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
5,277
Cooling degree days, base 65°F
992
Growing degree days, base 40°F
5,711
Growing degree days, base 45°F
4,463
Growing degree days, base 50°F
3,377
Growing degree days, base 55°F
2,434
Growing degree days, base 60°F
1,641

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07702
February89701
March752119
April4107125
May15355370
June27194616
July1337801
August5271732
September65117503
October34411171
November629033
December91705

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 11.1 km from Newtown Grant. 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 USC00284635 (Lambertville). Public domain.