Lanham-Seabrook climate

Lanham-Seabrook Frost Dates and Growing Season

NOAA 1991-2020 normals for Beltsville, 9.8 km from Lanham-Seabrook, elevation 145 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Beltsville. 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 10 and the first fall freeze around November 1, a growing season of about 202 days.

Median at 36°F
last April 24, first October 21
Median at 32°F
last April 10, first November 1
Median at 28°F
last March 29, first November 11

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 11May 6May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 10
32°FMay 1Apr 21Apr 18Apr 14Apr 10Apr 7Apr 3Mar 31Mar 27
28°FApr 10Apr 5Apr 2Mar 31Mar 29Mar 26Mar 22Mar 17Mar 12
24°FMar 31Mar 27Mar 22Mar 19Mar 16Mar 12Mar 9Mar 5Feb 27
20°FMar 21Mar 16Mar 12Mar 8Mar 5Mar 1Feb 25Feb 19Feb 10
16°FMar 12Mar 6Feb 28Feb 25Feb 20Feb 14Feb 8Feb 2Jan 26

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 7Oct 11Oct 15Oct 17Oct 21Oct 23Oct 26Oct 29Nov 2
32°FOct 16Oct 22Oct 26Oct 29Nov 1Nov 2Nov 5Nov 8Nov 14
28°FOct 29Nov 3Nov 6Nov 8Nov 11Nov 15Nov 18Nov 23Nov 30
24°FNov 9Nov 14Nov 18Nov 22Nov 26Dec 1Dec 4Dec 8Dec 16
20°FNov 21Dec 1Dec 5Dec 8Dec 13Dec 18Dec 23Dec 28Jan 4
16°FDec 8Dec 13Dec 19Dec 25Dec 30Jan 1Jan 6Jan 13Jan 22

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°F197191186182178174169164158
32°F221215210206202198193187180
28°F251243237233229225220216210
24°F281272265260255250245240232
20°F309301296290285280275267259
16°F337328322315309305300294286

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
99% 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
4,568
Cooling degree days, base 65°F
1,269
Growing degree days, base 40°F
6,453
Growing degree days, base 45°F
5,109
Growing degree days, base 50°F
3,927
Growing degree days, base 55°F
2,898
Growing degree days, base 60°F
2,012

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January96107
February80508
March660148
April33218188
May11985433
June13253690
July0383848
August1337801
September37166579
October26324250
November550162
December828013

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 9.8 km from Lanham-Seabrook. 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 USC00180700 (Beltsville). Public domain.