WASHINGTON, DISTRICT OF COLUMBIA

Average Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		58.2		36		39		46.8		56.8		66		75.2		79.8		78.1		71		59.5		49.6		39.7

Average High Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		66.8		43.4		47.1		55.9		66.6		75.4		84.2		88.4		86.5		79.5		68.4		57.9		46.8

Average Low Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		49.6		28.6		30.9		37.6		47		56.5		66.3		71.1		69.7		62.4		50.6		41.2		32.5

Highest Recorded Temperature

Years on Record: 71

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		105		79		82		89		95		99		104		105		105		101		94		86		79

Lowest Recorded Temperature

Years on Record: 71

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		-5		-5		4		11		24		34		47		54		49		39		29		16		1

Average Heat Index Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		58.4		36.1		38.9		46.6		56.8		66.1		75.8		81.2		79		71.1		59.4		49.2		39.9

Average Wind Chill Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		55.8		29.7		33.1		42.6		55.3		65.8		74.9		79.4		77.6		70.7		58.6		46.5		34.6

Average Number of Days Above 100F/38C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.7		---		---		---		---		---		---		0.4		0.2		---		---		---		---

Average Number of Days Above 90F/32C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		31		---		---		---		0.3		1.1		6.3		12.4		8.4		2.4		0.1		---		---

Average Number of Days Above 80F/26C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		109.8		---		---		0.7		3.4		10		22.8		28.5		27.2		14.4		2.7		0.1		---

Average Number of Days Above 70F/21C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		171.6		0.1		0.6		3.4		10.5		22.6		29		30.9		30.8		26.8		13		3.1		0.5

Average Number of Days Above 60F/15C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		231.5		2.4		3.3		10.9		21.7		29.8		30		31		31		29.8		25.9		12.6		3

Average Number of Days Above 50F/10C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		285.5		8.1		10.3		20.6		28.3		31		30		31		31		30		30.7		23.4		11.1

Average Number of Days Above 40F/4C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		335.3		18.8		21.1		28.8		30		31		30		31		31		30		31		29.3		23.4

Average Number of Days Below 70F/21C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		316.7		31		28		31		30		30.4		21		11.8		15		26.6		30.8		30		31

Average Number of Days Below 60F/15C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		244.5		31		28		30.9		28.6		21.4		4.9		0.2		0.9		10.5		27.3		29.7		31

Average Number of Days Below 50F/10C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		186		30.7		27.7		28.9		20.6		5.9		0.1		---		0.1		1.3		14.8		25.6		30.3

Average Number of Days Below 40F/4C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		119.5		28.3		24.5		19.4		5		0.1		---		---		---		---		2.4		14		25.8

Average Number of Days Below 32F/0C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		60.6		19.3		15.7		7.1		0.5		---		---		---		---		---		---		3.5		14.5

Average Number of Days Below 20F/-6C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		10.4		5.7		2.4		0.4		---		---		---		---		---		---		---		---		1.9

Average Number of Days Below 10F/-12C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.9		0.6		0.1		---		---		---		---		---		---		---		---		---		0.2

Average Number of Days Below 0F/-17C

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.1		0.1		---		---		---		---		---		---		---		---		---		---		---

Average Precipitation

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in.		39.7		2.8		2.6		3.5		3.1		4		3.8		3.7		2.9		3.7		3.4		3.2		3.1

Average Number of Days With Precipitation

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		114.1		9.6		9		10.5		10.4		11.1		10.7		10.3		8.2		8.3		7.7		8.6		9.7

Avg. No. of Days w/Precip. Above 0.1in/2.5mm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		70.1		5.6		5.4		6.5		6.5		7.3		6.1		6.3		5.2		5.5		4.8		5.3		5.6

Avg. No. of Days w/Precip. Above 0.5in/13mm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		28.5		2.1		1.7		2.4		2.2		2.9		2.5		3		2.1		2.4		2.5		2.3		2.4

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

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		9.4		0.6		0.3		0.9		0.6		0.9		1		1		0.7		1		1		0.9		0.5

Average Precipitable Water

Years on Record: 20

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in.		0.8		0.4		0.4		0.5		0.7		0.9		1.3		1.5		1.4		1.1		0.8		0.6		0.5

Average Number of Rainy Days

Years on Record: 52

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		112		10		9		11		10		11		9		10		9		8		7		9		9

Average Number of Days With Thunderstorms

Years on Record: 50

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		31		---		---		1		3		5		6		7		5		2		1		1		---

Most Rain Reported in a Month

Years on Record: 51

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in.		57.5		7.1		5.7		8.4		6.9		10.7		11.5		12.9		14.3		12.4		8.6		6.7		6.5

Least Recorded Rainfall

Years on Record: 51

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in.		26.9		0.3		0.4		0.7		---		0.8		0.9		0.9		0.5		0.2		---		0.3		0.2

Average Snowfall

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in.		15.4		5.6		5.7		1.3		---		---		---		---		---		---		---		0.5		2.3

Average Number of Days With Snow

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		8.1		3		2.4		0.9		0.1		---		---		---		---		---		---		0.2		1.5

Avg. No. of Days w/Snow Above 1in/2.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		4.1		1.6		1.3		0.4		---		---		---		---		---		---		---		0.1		0.7

Avg. No. of Days w/Snow Above 3in/7.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1.6		0.6		0.7		0.1		---		---		---		---		---		---		---		---		0.2

Avg. No. of Days w/Snow Above 5in/12.7cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.7		0.2		0.3		0.1		---		---		---		---		---		---		---		---		0.1

Avg. No. of Days w/Snowfall Above 10in/25cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.2		0.1		0.1		---		---		---		---		---		---		---		---		---		---

Avg. # of Days w/Snow Depth Above 1in/2.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		12.1		4.5		4.6		0.8		---		---		---		---		---		---		---		0.2		2

Avg. # of Days w/Snow Depth Above 3in/7.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		6.7		2.5		2.7		0.4		---		---		---		---		---		---		---		0.1		1

Avg. # of Days w/Snow Depth Above 5in/12.7cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		3.9		1.7		1.6		0.1		---		---		---		---		---		---		---		0.1		0.4

Avg. # of Days w/Snow Depth Above 10in/25cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1.4		0.6		0.7		---		---		---		---		---		---		---		---		---		0.1

Average Relative Humidity

Years on Record: 20

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		65		62.1		59.4		58.7		60.9		65.9		68.2		66.4		68.5		69.6		69.7		66.2		63.1

Average Morning Relative Humidity

Years on Record: 54

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		75		71		70		70		70		75		76		77		81		82		81		76		72

Average Evening Relative Humidity

Years on Record: 54

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		52		55		50		47		46		51		52		53		54		55		53		53		55

Average Dew Point

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		45.4		23.8		25.7		31.5		41.9		52.9		62.4		66.3		65.6		59.5		48.4		37.5		28.2

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		4030		899		728		568		270		79		6		---		---		24		205		466		786

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1550		---		---		2		24		108		314		457		406		202		34		2		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		4416		9		13		71		232		495		757		922		871		628		304		96		17

Average Sea Level Pressure

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
InHg		30.1		30.1		30.1		30.1		30		30		30		30		30		30.1		30.1		30.1		30.1

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		12.4		13.7		14.8		15.4		15.1		14.1		12.8		11.6		10.5		10

Average Number of Days With Fog

Years on Record: 50

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		130		11		10		10		9		12		10		10		11		12		13		11		11

Average Number of Clear Days

Years on Record: 45

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		97		8		7		7		7		7		8		7		9		10		11		8		8

Average Possibility of Sunshine

Years on Record: 45

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		56		47		51		55		56		58		64		62		62		61		59		51		46

Average Number of Cloudy Days

Years on Record: 45

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		163		16		14		15		14		14		11		12		12		12		12		14		16

Average Number of Partly Cloudy Days

Years on Record: 45

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		105		7		7		9		9		10		11		12		10		8		8		8		7

Average Percent Chance - Clear Skies

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		15.8		16.5		16.6		17.7		16.2		13.3		10.4		10.2		12.6		18.4		22.5		18.6		16.2

Average Percent Chance - Scattered Clouds

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		9		7.2		7.5		6.7		7.7		9.2		12.5		12.7		12.2		9.8		8		7.7		7.1

Average Percent Chance - Few Clouds

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		17		14.7		15.4		15.7		15.5		17.1		18.7		19.6		19.5		19		17.6		16		15

Average Percent Chance - Broken Clouds

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		20.4		16.8		16.4		16.9		18.7		21.3		26.4		28.4		25.8		20		18.3		18.6		17.4

Average Percent Chance - Overcast Skies

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		37.8		44.8		44.1		43		41.9		39.1		32.1		29.1		30		32.8		33.5		39		44.1

Average Total Sky Cover

Years on Record: 20

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		60.7		64.1		62.1		62.7		61.9		62.2		62		60.9		58		55.9		53.2		60.4		63.4

Average Opaque Sky Cover

Years on Record: 20

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		53.9		58.2		56		57		53.9		55.3		54.4		54.1		48.9		50		47.7		53.4		57.5

Average Wind Speed

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mph		9.1		9.6		9.9		10.6		10.1		9.1		8.6		8.2		7.9		8.3		8.5		9		9.3

Highest Reported Hourly Wind Speed

Years on Record: 27

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mph		49		43		41		46		44		46		49		47		47		45		41		43		40

Average Percent Chance - Calm Winds

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		5.7		5.8		6.4		4.4		4.8		4.6		4.7		5.2		5.7		6.4		6.7		7.9		6.4

Average Primary Wind Direction

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
°		270.5		360		360		347.5		264.2		225.6		225.9		229.4		210		186.8		209.2		278.9		353

Average Secondary Wind Direction

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
°		244.8		212.8		202.6		223.5		283.9		302.8		294.9		271.6		196.1		200.3		266.3		279.4		201.3

Average Wind Vector Direction

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
°		270.3		307.6		310.6		311.2		297		249.1		223		231.3		200.4		221.6		294.1		297.2		303.5

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.9		2		2.8		3.7		4.7		5.3		5.6		5.6		5		4.3		3.4		2.2		1.7

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.6		0.8		1.1		1.5		2		2.3		2.5		2.4		2.1		1.7		1.2		0.9		0.7

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		4.3		3.1		3.7		4.3		4.7		4.9		4.9		5		4.8		4.7		4.5		3.4		2.9

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		4.2		3.1		3.7		4.1		4.4		4.7		4.8		4.9		4.6		4.6		4.6		3.5		2.9

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.9		2		2.8		3.7		4.7		5.3		5.6		5.6		5		4.3		3.4		2.2		1.7

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.7		0.8		1.2		1.6		2.1		2.4		2.5		2.5		2.2		1.7		1.3		0.9		0.8

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		5		3.7		4.6		5.3		5.4		5.8		5.7		5.4		5.4		5.5		5.7		4.3		3.4

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		5.4		3.9		5.2		5.5		5.6		6.4		6.6		5.8		5.6		6		6.4		4.8		3.6

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.2		1.7		2.2		3		4		3.5		4.7		5		4.4		3.7		2.7		1.6		1.3

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.5		0.8		1		1.4		1.9		2.2		2.3		2.3		2		1.5		1		0.8		0.7

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.4		2.5		2.8		3.4		4		3.3		4.2		4.5		4.2		3.9		3.4		2.2		2

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		2.8		2.3		2.4		2.7		3.3		2		3.4		3.9		3.6		3.4		3		1.9		1.8