Kings Bay Base climate

Kings Bay Base Frost Dates and Growing Season

NOAA 1991-2020 normals for Brunswick 23 S, 10.2 km from Kings Bay Base, elevation 25 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brunswick 23 S. 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 February 19 and the first fall freeze around December 14, a growing season of about 299 days.

Median at 36°F
last March 5, first November 29
Median at 32°F
last February 19, first December 14
Median at 28°F
last February 3, first January 3

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°FMar 31Mar 20Mar 16Mar 11Mar 5Mar 1Feb 26Feb 21Feb 12
32°FMar 14Mar 5Feb 28Feb 24Feb 19Feb 13Feb 7Jan 31Jan 19
28°FFeb 28Feb 20Feb 12Feb 7Feb 3Jan 30Jan 23Jan 13Dec 31
24°FFeb 15Feb 8Feb 3Jan 31Jan 25Jan 18Jan 13Jan 3Dec 24
20°F–––––––––
16°F–––––––––

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°FNov 11Nov 17Nov 20Nov 24Nov 29Dec 1Dec 6Dec 12Dec 22
32°FNov 21Nov 29Dec 3Dec 8Dec 14Dec 22Dec 30Jan 4Jan 15
28°FDec 2Dec 11Dec 20Dec 29Jan 3Jan 9Jan 17Jan 26Feb 7
24°FDec 11Dec 25Jan 1Jan 8Jan 15Jan 20Jan 26Feb 1Feb 9
20°F–––––––––
16°F–––––––––

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°F299287279273267261255248239
32°F332321313306299292285276264
28°F365357344336331324315307296
24°F365365365365365357345333321
20°F365365365365365365365365365
16°F365365365365365365365365365

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
98% of years
28°F or colder
84% of years
24°F or colder
45% of years
20°F or colder
8% of years
16°F or colder
0% 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
1,423
Cooling degree days, base 65°F
2,464
Growing degree days, base 40°F
10,184
Growing degree days, base 45°F
8,404
Growing degree days, base 50°F
6,698
Growing degree days, base 55°F
5,116
Growing degree days, base 60°F
3,689

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January3906158
February28811182
March17834331
April5594490
May4269730
June0417867
July0501966
August0499964
September0386835
October30193628
November16243339
December31512209

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 10.2 km from Kings Bay Base. 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 USW00063856 (Brunswick 23 S). Public domain.