New Hope climate

New Hope Frost Dates and Growing Season

NOAA 1991-2020 normals for Owens Cross Roads 3S, 5 km from New Hope, elevation 590 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Owens Cross Roads 3S. 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 4 and the first fall freeze around October 30, a growing season of about 210 days.

Median at 36°F
last April 16, first October 22
Median at 32°F
last April 4, first October 30
Median at 28°F
last March 24, first November 8

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°FApr 30Apr 26Apr 22Apr 19Apr 16Apr 12Apr 9Apr 5Mar 31
32°FApr 20Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 24Mar 18
28°FApr 9Apr 4Mar 31Mar 27Mar 24Mar 19Mar 15Mar 10Mar 2
24°FMar 30Mar 23Mar 17Mar 13Mar 8Mar 4Feb 28Feb 22Feb 13
20°FMar 15Mar 8Mar 2Feb 27Feb 20Feb 15Feb 8Feb 2Jan 23
16°FMar 3Feb 25Feb 16Feb 8Feb 4Jan 31Jan 24Jan 17Jan 7

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 8Oct 13Oct 17Oct 19Oct 22Oct 23Oct 26Oct 29Nov 2
32°FOct 17Oct 21Oct 25Oct 27Oct 30Nov 1Nov 4Nov 7Nov 13
28°FOct 26Oct 31Nov 3Nov 5Nov 8Nov 11Nov 15Nov 20Nov 30
24°FNov 5Nov 9Nov 14Nov 17Nov 21Nov 25Nov 30Dec 5Dec 14
20°FNov 15Nov 21Nov 27Dec 1Dec 6Dec 12Dec 23Dec 31Jan 9
16°FDec 1Dec 8Dec 16Dec 25Jan 1Jan 5Jan 10Jan 16Jan 30

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°F209201196192188184180175169
32°F229222218214210205201196189
28°F256247241236231226221215207
24°F290278270263257251245238230
20°F328314304296290282275267255
16°F363348337331324315306298288

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
91% 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
3,484
Cooling degree days, base 65°F
1,509
Growing degree days, base 40°F
7,473
Growing degree days, base 45°F
5,964
Growing degree days, base 50°F
4,600
Growing degree days, base 55°F
3,404
Growing degree days, base 60°F
2,376

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January777032
February606143
March4464127
April21630284
May59124531
June1291739
July0408873
August0385849
September20215645
October18648342
November480492
December695043

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 5 km from New Hope. 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 USC00016196 (Owens Cross Roads 3S). Public domain.