Lambertville climate

Lambertville Frost Dates and Growing Season

NOAA 1991-2020 normals for Dundee, 21.1 km from Lambertville, elevation 660 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dundee. 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 27 and the first fall freeze around October 21, a growing season of about 176 days.

Median at 36°F
last May 6, first October 8
Median at 32°F
last April 27, first October 21
Median at 28°F
last April 16, 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 22May 17May 13May 9May 6May 4May 1Apr 28Apr 23
32°FMay 13May 7May 2Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14
28°FMay 2Apr 26Apr 22Apr 19Apr 16Apr 13Apr 10Apr 6Apr 3
24°FApr 18Apr 13Apr 9Apr 6Apr 4Apr 2Mar 31Mar 26Mar 20
20°FApr 7Apr 3Mar 31Mar 29Mar 26Mar 22Mar 18Mar 15Mar 10
16°FMar 31Mar 26Mar 22Mar 19Mar 16Mar 13Mar 9Mar 5Feb 28

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 26Sep 30Oct 2Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21
32°FOct 6Oct 11Oct 15Oct 18Oct 21Oct 23Oct 26Oct 29Nov 1
28°FOct 19Oct 24Oct 27Oct 31Nov 1Nov 3Nov 6Nov 10Nov 14
24°FNov 1Nov 3Nov 6Nov 9Nov 12Nov 15Nov 17Nov 22Nov 27
20°FNov 8Nov 13Nov 17Nov 21Nov 24Nov 28Dec 1Dec 5Dec 13
16°FNov 18Nov 24Nov 29Dec 1Dec 5Dec 10Dec 14Dec 19Dec 26

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°F172166161157154151147142135
32°F193187183179176172167163156
28°F217211207202198194190185178
24°F243235230226222217214210204
20°F268259253248244239235228223
16°F288279274270265260255249242

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
6,373
Cooling degree days, base 65°F
732
Growing degree days, base 40°F
5,025
Growing degree days, base 45°F
3,903
Growing degree days, base 50°F
2,915
Growing degree days, base 55°F
2,057
Growing degree days, base 60°F
1,325

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,24901
February1,07101
March911117
April533377
May22339297
June34156572
July4258719
August10194649
September10472421
October4149139
November744021
December1,07702

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 21.1 km from Lambertville. 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 USC00202308 (Dundee). Public domain.