Shrub Oak climate

Shrub Oak Frost Dates and Growing Season

NOAA 1991-2020 normals for Shrub Oak, 1.5 km from Shrub Oak, elevation 462 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Shrub Oak. 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 30 and the first fall freeze around October 17, a growing season of about 172 days.

Median at 36°F
last May 10, first October 7
Median at 32°F
last April 30, first October 17
Median at 28°F
last April 17, 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 26May 20May 16May 12May 10May 7May 3May 1Apr 27
32°FMay 13May 8May 5May 2Apr 30Apr 27Apr 23Apr 20Apr 16
28°FMay 1Apr 27Apr 23Apr 20Apr 17Apr 14Apr 11Apr 8Apr 3
24°FApr 17Apr 12Apr 8Apr 5Apr 3Apr 1Mar 30Mar 27Mar 20
20°FApr 5Apr 1Mar 30Mar 27Mar 24Mar 20Mar 17Mar 13Mar 7
16°FMar 28Mar 23Mar 19Mar 16Mar 13Mar 9Mar 6Mar 1Feb 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 25Sep 30Oct 2Oct 4Oct 7Oct 9Oct 13Oct 16Oct 22
32°FOct 4Oct 9Oct 12Oct 14Oct 17Oct 21Oct 25Oct 28Nov 3
28°FOct 16Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 8Nov 13
24°FOct 27Nov 1Nov 3Nov 7Nov 10Nov 13Nov 16Nov 20Nov 27
20°FNov 5Nov 11Nov 15Nov 19Nov 22Nov 27Nov 30Dec 3Dec 9
16°FNov 18Nov 25Nov 29Dec 2Dec 6Dec 10Dec 15Dec 20Dec 28

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°F170164159154151146142137130
32°F192186181176172168163158152
28°F215208203199195191187183175
24°F242233228224220215211206199
20°F268259253249244240235230223
16°F293285280274269265259253245

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
6,014
Cooling degree days, base 65°F
636
Growing degree days, base 40°F
4,945
Growing degree days, base 45°F
3,806
Growing degree days, base 50°F
2,800
Growing degree days, base 55°F
1,936
Growing degree days, base 60°F
1,210

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,18200
February99800
March87103
April508275
May21221284
June39102513
July1231694
August6207666
September11071411
October3882132
November696023
December1,00300

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 1.5 km from Shrub Oak. 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 USC00307742 (Shrub Oak). Public domain.