Monarch Mill climate

Monarch Mill Frost Dates and Growing Season

NOAA 1991-2020 normals for Santuck, 10.8 km from Monarch Mill, elevation 520 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Santuck. 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 November 1, a growing season of about 210 days.

Median at 36°F
last April 15, first October 23
Median at 32°F
last April 4, first November 1
Median at 28°F
last March 24, first November 10

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 18Apr 15Apr 12Apr 9Apr 6Apr 1
32°FApr 20Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 25Mar 19
28°FApr 9Apr 3Mar 31Mar 28Mar 24Mar 21Mar 17Mar 13Mar 5
24°FMar 29Mar 23Mar 19Mar 16Mar 12Mar 8Mar 2Feb 24Feb 16
20°FMar 19Mar 13Mar 7Mar 1Feb 24Feb 18Feb 12Feb 3Jan 28
16°FMar 8Feb 27Feb 18Feb 10Feb 3Jan 30Jan 25Jan 15Jan 5

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

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°F209202197193189186182177171
32°F230223218214210206203198191
28°F257249243237233228224219213
24°F290279271265260254249243234
20°F324311303296290283276266258
16°F359345336330322314306297285

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
92% 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
2,956
Cooling degree days, base 65°F
1,767
Growing degree days, base 40°F
8,104
Growing degree days, base 45°F
6,515
Growing degree days, base 50°F
5,083
Growing degree days, base 55°F
3,810
Growing degree days, base 60°F
2,702

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January682042
February518161
March36711178
April14552364
May32176610
June2354802
July0470935
August0417882
September15229664
October15750366
November4186125
December619155

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 10.8 km from Monarch Mill. 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 USC00387722 (Santuck). Public domain.