FREDERICK, MARYLAND

Average Temperature

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		12		1		1		6		11		17		21		24		23		19		13		6		2

Average High Temperature

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		18		5		6		12		18		25		28		31		30		26		20		12		6

Average Low Temperature

Years on Record: 66

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		6		-3		-3		---		5		10		15		18		17		13		7		1		-2

Highest Recorded Temperature

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		42		24		26		32		36		37		40		42		41		38		37		28		23

Lowest Recorded Temperature

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-29		-29		-24		-18		-10		-4		3		5		3		-2		-5		-15		-28

Average Number of Days Above 90F/32C

Years on Record: 11

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		28		---		---		---		---		1		5		10		7		3		---		---		---

Average Number of Days Below 32F/0C

Years on Record: 11

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		123		28		23		20		6		---		---		---		---		---		3		16		24

Average Number of Days Below 0F/-17C

Years on Record: 11

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1		---		---		---		---		---		---		---		---		---		---		---		---

Average Precipitation

Years on Record: 82

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		1020		70		70		80		80		90		100		100		90		80		70		60		70

Average Number of Days With Precipitation

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		98		8		7		9		9		10		9		9		9		7		7		8		7

Most Precipitation Reported in a Day

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm.		196.8		53.9		58.2		85.1		68.1		101.6		196.8		102.1		124.5		144		92.7		68.8		63.5

Avg. No. of Days w/Precip. Above 0.2in/5mm

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		74		6		6		7		7		8		7		6		6		5		5		6		6

Avg. # of Days w/Precip. Above 0.4in/10mm

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		29		2		2		3		3		3		3		2		2		2		2		2		2

Avg. No. of Days w/Precip. Above 1in/25mm

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		9		1		---		1		1		1		1		1		1		1		1		1		1

Average Number of Rainy Days

Years on Record: 82

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		73		6		6		6		6		6		6		6		6		5		4		4		6

Most Rain Reported in a Month

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		1397		200		148		179		265		292		329		199		267		286		372		173		193

Least Rain Reported in a Month

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		792		8		3		35		10		5		24		26		2		15		9		18		---

Average Snowfall

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm.		62		21.1		17.3		8.6		1		---		---		---		---		---		0.2		2		11.7

Most Snow Reported in a Month

Years on Record: 42

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm.		129.5		76.2		73.7		55.9		10.2		---		---		---		---		---		5.1		25.4		76.2

Average Relative Humidity

Years on Record: 44

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		66		65		68		60		60		60		69		66		70		71		71		71		63

Average Dew Point

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		5		-6		-5		-2		3		8		15		17		17		13		7		1		-5

Heating Degree Days

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		3035.2		551.1		486.6		378.9		191.7		17.2		---		---		---		---		146.4		333.3		516.7

Cooling Degree Days

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		537		---		---		---		---		---		116.7		206.7		163.6		50		---		---		---

Growing Degree Days

Years on Record: 67

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1964.9		---		---		---		58.3		241.1		366.7		465		421.9		300		111.9		---		---

Average Length of Day

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Hours		12.7		10.3		11.2		12.5		13.8		14.9		15.4		15.1		14.1		12.9		11.6		10.5		9.9

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.9		7.1		9.9		13.4		16.8		19.2		20.3		20.1		17.9		15.3		12.1		8		6.2

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.8		3		4		5.5		7.2		8.3		8.9		8.6		7.6		5.9		4.3		3.2		2.7

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		15.3		11.2		13.4		15.6		17		17.6		17.8		17.9		17.3		17		16.3		12.3		10.3

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		15		11.3		13.4		14.7		15.8		16.9		17.4		17.6		16.4		16.6		16.6		12.6		10.4

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.9		7.1		9.9		13.4		16.8		19.2		20.3		20.1		17.9		15.3		12.1		8		6.2

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.9		3		4.1		5.7		7.4		8.6		9.1		8.8		7.8		6.3		4.6		3.3		2.7

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		18.1		13.4		16.7		18.9		19.4		20.7		20.7		19.5		19.3		19.9		20.6		15.6		12.3

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.6		14		18.5		19.8		20		23.1		23.6		20.8		20		21.5		23.1		17.4		13

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		11.4		6		7.9		10.8		14.5		12.7		17.1		17.9		15.8		13.1		9.8		5.9		4.8

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.4		2.8		3.6		5.1		6.8		7.7		8.3		8.3		7.3		5.4		3.5		2.8		2.6

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.1		9		9.9		12.1		14.5		11.7		15.1		16.1		15.3		14.1		12.3		8.1		7.2

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		10.1		8.3		8.6		9.7		11.8		7.2		12.1		13.9		12.9		12.2		10.8		7		6.4