Millville climate

Millville Frost Dates and Growing Season

NOAA 1991-2020 normals for Millville Muni AP, 4.6 km from Millville, elevation 70 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Millville Muni AP. 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 24 and the first fall freeze around October 23, a growing season of about 181 days.

Median at 36°F
last May 6, first October 14
Median at 32°F
last April 24, first October 23
Median at 28°F
last April 10, first November 2

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 22May 16May 12May 9May 6May 2Apr 29Apr 25Apr 21
32°FMay 10May 5May 1Apr 27Apr 24Apr 21Apr 19Apr 15Apr 8
28°FApr 26Apr 20Apr 17Apr 14Apr 10Apr 7Apr 4Mar 31Mar 26
24°FApr 11Apr 5Apr 2Mar 30Mar 27Mar 24Mar 21Mar 17Mar 11
20°FMar 31Mar 26Mar 22Mar 19Mar 15Mar 11Mar 8Mar 4Feb 26
16°FMar 21Mar 16Mar 11Mar 7Mar 4Feb 28Feb 25Feb 19Feb 9

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 2Oct 6Oct 9Oct 11Oct 14Oct 16Oct 19Oct 23Oct 28
32°FOct 10Oct 13Oct 17Oct 20Oct 23Oct 25Oct 29Nov 1Nov 5
28°FOct 19Oct 25Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 17
24°FNov 1Nov 3Nov 7Nov 11Nov 14Nov 18Nov 22Nov 27Dec 2
20°FNov 10Nov 17Nov 21Nov 25Nov 29Dec 1Dec 5Dec 11Dec 18
16°FNov 24Dec 1Dec 5Dec 9Dec 14Dec 18Dec 22Dec 26Jan 4

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°F181175170165161157153148141
32°F202195190186181177172167160
28°F228222215212208203199194186
24°F255248242237232229224219212
20°F283274268263258252247241234
16°F313303297291285280274268259

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
4,934
Cooling degree days, base 65°F
1,050
Growing degree days, base 40°F
5,989
Growing degree days, base 45°F
4,689
Growing degree days, base 50°F
3,550
Growing degree days, base 55°F
2,570
Growing degree days, base 60°F
1,737

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January99206
February85106
March718131
April39610137
May15955365
June22199627
July0346811
August2291755
September51129528
October29918218
November586153
December859013

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 4.6 km from Millville. 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 USW00013735 (Millville Muni AP). Public domain.