Spring Grove climate

Spring Grove Frost Dates and Growing Season

NOAA 1991-2020 normals for York AP, 4.8 km from Spring Grove, elevation 486 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for York 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 27 and the first fall freeze around October 18, a growing season of about 174 days.

Median at 36°F
last May 8, first October 7
Median at 32°F
last April 27, first October 18
Median at 28°F
last April 12, first October 30

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 23May 18May 14May 10May 8May 4May 1Apr 28Apr 24
32°FMay 11May 7May 3Apr 30Apr 27Apr 24Apr 21Apr 17Apr 12
28°FApr 29Apr 23Apr 18Apr 16Apr 12Apr 10Apr 6Apr 3Mar 30
24°FApr 14Apr 9Apr 6Apr 3Apr 1Mar 30Mar 27Mar 23Mar 15
20°FApr 3Mar 31Mar 27Mar 24Mar 21Mar 17Mar 14Mar 10Mar 5
16°FMar 26Mar 20Mar 16Mar 13Mar 9Mar 6Mar 2Feb 27Feb 21

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 4Oct 7Oct 9Oct 12Oct 15Oct 20
32°FOct 4Oct 8Oct 12Oct 15Oct 18Oct 21Oct 25Oct 29Nov 1
28°FOct 13Oct 19Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 11
24°FOct 25Oct 31Nov 3Nov 6Nov 9Nov 12Nov 15Nov 19Nov 26
20°FNov 6Nov 11Nov 15Nov 18Nov 22Nov 25Nov 29Dec 4Dec 11
16°FNov 18Nov 26Dec 1Dec 3Dec 7Dec 11Dec 16Dec 21Dec 27

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°F171165161157153149144139133
32°F194187183179174170166160153
28°F218212207202198193189185179
24°F245238231226222218214209202
20°F274264258252248243238232225
16°F298288282277272268263257248

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
5,423
Cooling degree days, base 65°F
853
Growing degree days, base 40°F
5,544
Growing degree days, base 45°F
4,309
Growing degree days, base 50°F
3,226
Growing degree days, base 55°F
2,292
Growing degree days, base 60°F
1,497

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08204
February92304
March766028
April4248123
May17150350
June22178606
July2285749
August6230688
September8089460
October35612171
November647034
December94609

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 4.8 km from Spring Grove. 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 USW00093778 (York AP). Public domain.