Hammonton climate

Hammonton Frost Dates and Growing Season

NOAA 1991-2020 normals for Hammonton 1 Ne, 0.8 km from Hammonton, elevation 125 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hammonton 1 Ne. 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 14 and the first fall freeze around October 27, a growing season of about 196 days.

Median at 36°F
last April 27, first October 16
Median at 32°F
last April 14, first October 27
Median at 28°F
last April 2, first November 5

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 12May 6May 2Apr 30Apr 27Apr 24Apr 21Apr 18Apr 13
32°FApr 27Apr 22Apr 19Apr 17Apr 14Apr 11Apr 8Apr 5Apr 1
28°FApr 16Apr 11Apr 7Apr 4Apr 2Mar 31Mar 29Mar 25Mar 21
24°FApr 3Mar 31Mar 28Mar 25Mar 22Mar 20Mar 17Mar 13Mar 8
20°FMar 26Mar 22Mar 19Mar 16Mar 13Mar 9Mar 7Mar 3Feb 27
16°FMar 19Mar 14Mar 10Mar 7Mar 3Feb 28Feb 24Feb 18Feb 11

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 8Oct 11Oct 14Oct 16Oct 19Oct 22Oct 26Oct 31
32°FOct 13Oct 17Oct 21Oct 24Oct 27Oct 29Nov 1Nov 3Nov 8
28°FOct 24Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19
24°FNov 2Nov 7Nov 10Nov 13Nov 17Nov 20Nov 24Nov 28Dec 3
20°FNov 13Nov 19Nov 24Nov 28Dec 1Dec 4Dec 10Dec 15Dec 23
16°FNov 26Dec 2Dec 7Dec 14Dec 19Dec 24Dec 29Jan 3Jan 12

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°F190184179175172168163158151
32°F214207203199196192187182175
28°F237229224220217213209204197
24°F262254249244240236231225219
20°F293282275269264260255249242
16°F315306301295291286280273263

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
4,880
Cooling degree days, base 65°F
1,115
Growing degree days, base 40°F
6,091
Growing degree days, base 45°F
4,788
Growing degree days, base 50°F
3,643
Growing degree days, base 55°F
2,654
Growing degree days, base 60°F
1,809

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January99706
February84407
March727030
April39112140
May14960378
June19219650
July0369834
August1304767
September45133539
October28719226
November575155
December845012

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 0.8 km from Hammonton. 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 USC00283662 (Hammonton 1 Ne). Public domain.