Forestbrook climate

Forestbrook Frost Dates and Growing Season

NOAA 1991-2020 normals for Myrtle Beach, 13.1 km from Forestbrook, elevation 39 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Myrtle Beach. 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 March 21 and the first fall freeze around November 13, a growing season of about 239 days.

Median at 36°F
last April 3, first November 3
Median at 32°F
last March 21, first November 13
Median at 28°F
last March 7, first November 26

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 18Apr 11Apr 8Apr 6Apr 3Mar 31Mar 27Mar 23Mar 16
32°FApr 7Apr 2Mar 29Mar 26Mar 21Mar 18Mar 14Mar 9Mar 2
28°FMar 28Mar 21Mar 16Mar 12Mar 7Mar 3Feb 27Feb 21Feb 8
24°FMar 13Mar 6Feb 28Feb 24Feb 16Feb 9Feb 3Jan 30Jan 19
20°FFeb 27Feb 17Feb 7Feb 2Jan 30Jan 25Jan 18Jan 11Dec 31
16°FFeb 13Feb 2Jan 30Jan 25Jan 21Jan 16Jan 11Jan 7Dec 31

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 22Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 12Nov 18
32°FOct 31Nov 3Nov 7Nov 10Nov 13Nov 16Nov 19Nov 25Dec 3
28°FNov 7Nov 12Nov 17Nov 20Nov 26Dec 1Dec 4Dec 13Dec 26
24°FNov 16Nov 24Dec 1Dec 6Dec 16Dec 25Jan 1Jan 6Jan 14
20°FDec 1Dec 10Dec 23Dec 30Jan 4Jan 9Jan 16Jan 22Feb 1
16°FDec 18Dec 30Jan 3Jan 8Jan 13Jan 18Jan 22Jan 27Feb 3

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°F239231225220216212208203196
32°F265256249244239234229223216
28°F301288280274267261255248238
24°F335325315306301294286277265
20°F365361350340334329319309301
16°F365365365365365361349340328

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
99% of years
20°F or colder
84% of years
16°F or colder
44% 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
2,671
Cooling degree days, base 65°F
1,748
Growing degree days, base 40°F
8,307
Growing degree days, base 45°F
6,660
Growing degree days, base 50°F
5,167
Growing degree days, base 55°F
3,847
Growing degree days, base 60°F
2,706

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January634041
February514048
March3823148
April14830336
May26157597
June1337786
July0450914
August0411876
September4274720
October8878459
November3287173
December545169

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 13.1 km from Forestbrook. 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 USC00386153 (Myrtle Beach). Public domain.