Covington climate

Covington Frost Dates and Growing Season

NOAA 1991-2020 normals for Covington 4 Nnw, 5.8 km from Covington, elevation 40 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Covington 4 Nnw. 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 12 and the first fall freeze around November 18, a growing season of about 253 days.

Median at 36°F
last March 27, first November 7
Median at 32°F
last March 12, first November 18
Median at 28°F
last February 19, first December 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°FApr 15Apr 8Apr 4Mar 31Mar 27Mar 22Mar 17Mar 12Mar 3
32°FApr 3Mar 26Mar 21Mar 17Mar 12Mar 6Feb 28Feb 23Feb 13
28°FMar 17Mar 10Mar 3Feb 26Feb 19Feb 13Feb 4Jan 30Jan 18
24°FMar 4Feb 24Feb 13Feb 3Jan 31Jan 27Jan 19Jan 10Dec 31
20°FFeb 18Feb 4Jan 30Jan 27Jan 21Jan 15Jan 10Jan 4Dec 27
16°FFeb 10Jan 31Jan 27Jan 23Jan 17Jan 11Jan 6Jan 2Dec 23

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 24Oct 30Nov 1Nov 4Nov 7Nov 10Nov 14Nov 19Nov 25
32°FNov 1Nov 6Nov 10Nov 15Nov 18Nov 23Nov 27Dec 3Dec 12
28°FNov 12Nov 18Nov 24Nov 30Dec 3Dec 10Dec 20Jan 1Jan 6
24°FDec 1Dec 7Dec 15Dec 24Jan 1Jan 4Jan 9Jan 17Jan 31
20°FDec 11Dec 25Jan 1Jan 4Jan 7Jan 12Jan 18Jan 25Feb 2
16°FDec 18Dec 31Jan 3Jan 6Jan 10Jan 16Jan 21Jan 27Feb 1

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°F256246238232227222216210202
32°F290276268260253247240233222
28°F330317307300290283274265254
24°F365358345336330321311304289
20°F365365365365364354344336322
16°F365365365365365365365365349

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
99% of years
24°F or colder
85% of years
20°F or colder
50% of years
16°F or colder
16% 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
1,670
Cooling degree days, base 65°F
2,406
Growing degree days, base 40°F
9,888
Growing degree days, base 45°F
8,134
Growing degree days, base 50°F
6,473
Growing degree days, base 55°F
4,951
Growing degree days, base 60°F
3,590

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4467131
February30414176
March17845344
April66113497
May6271730
June0421871
July0487952
August0488953
September1364813
October56152563
November23132274
December38413170

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 5.8 km from Covington. 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 USC00162151 (Covington 4 Nnw). Public domain.