Hanover climate

Hanover Frost Dates and Growing Season

NOAA 1991-2020 normals for Hanover 4 Sw, 5.4 km from Hanover, elevation 558 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hanover 4 Sw. 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 20, a growing season of about 177 days.

Median at 36°F
last May 7, first October 8
Median at 32°F
last April 24, first October 20
Median at 28°F
last April 9, first October 31

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 18May 14May 10May 7May 3Apr 30Apr 26Apr 22
32°FMay 11May 6May 2Apr 28Apr 24Apr 21Apr 18Apr 14Apr 9
28°FApr 26Apr 20Apr 16Apr 12Apr 9Apr 6Apr 3Mar 31Mar 26
24°FApr 10Apr 5Apr 2Mar 31Mar 29Mar 25Mar 21Mar 18Mar 12
20°FMar 31Mar 26Mar 22Mar 18Mar 16Mar 13Mar 9Mar 4Feb 28
16°FMar 20Mar 15Mar 11Mar 8Mar 4Mar 2Feb 27Feb 22Feb 14

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 28Oct 1Oct 3Oct 6Oct 8Oct 11Oct 14Oct 17Oct 21
32°FOct 6Oct 9Oct 13Oct 17Oct 20Oct 23Oct 26Oct 30Nov 2
28°FOct 14Oct 20Oct 25Oct 28Oct 31Nov 2Nov 5Nov 9Nov 14
24°FOct 26Nov 1Nov 4Nov 7Nov 11Nov 14Nov 18Nov 22Nov 29
20°FNov 8Nov 13Nov 18Nov 22Nov 26Nov 29Dec 3Dec 8Dec 15
16°FNov 23Dec 1Dec 5Dec 9Dec 12Dec 16Dec 20Dec 25Jan 1

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°F174167162157154149145140133
32°F198191185181177172167162154
28°F224216211207203199194190181
24°F251244238233229225220215207
20°F280271265259254249244238231
16°F305297291286282277271265258

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
5,397
Cooling degree days, base 65°F
904
Growing degree days, base 40°F
5,603
Growing degree days, base 45°F
4,370
Growing degree days, base 50°F
3,289
Growing degree days, base 55°F
2,350
Growing degree days, base 60°F
1,553

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07705
February91304
March771128
April42211132
May17355354
June27185608
July2298761
August6246705
September7797471
October34812179
November642037
December93907

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 5.4 km from Hanover. 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 USC00363665 (Hanover 4 Sw). Public domain.