MERCER ISLAND, WASHINGTON

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Elevation: 69 meters Latitude: 47 32N Longitude: 122 18W

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CURRENT CONDITIONS

Sunrise/Set

08:58 am

11:14 pm
Local Time
3:05 pm EDT
26 April, 2024

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MONTHLY - ALL WEATHER AVERAGES [ Show Summary ]

[ °F ] °C

TEMPERATURE

Average Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		11.7		5.7		6.3		8.3		10.7		13.5		16.7		19.3		19.4		16.4		11.7		7.6		4.9

Average High Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		15.9		8.8		10.2		12.3		14.8		18.3		21.3		24.3		24.6		21.3		15.6		10.9		7.9

Average Low Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		7.6		2.6		2.4		4.4		6.6		8.6		12		14.2		14.3		11.6		7.7		4.3		1.9

Highest Recorded Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		27.2		11.1		13.3		15.1		17.3		21.8		24.3		27.2		26.7		24.4		18.6		12.9		9.9

Lowest Recorded Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-1.9		-1.3		-1.9		1.3		3.3		6.7		9.4		11.7		11.3		8.7		6.1		-0.6		-0.9

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		0.1		---		---		---		---		---		---		0.1		---		---		---		---		---

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		1.5		---		---		---		---		---		0.2		1		0.3		---		---		---		---

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		22.5		---		---		---		0.1		0.9		3.3		7.7		8.4		2.2		---		---		---

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		88.9		---		---		0.2		2		6.4		13.5		24		26.4		15.5		1		---		---

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		174.9		0.3		0.6		3.9		10.6		23.7		28.2		31		31		29.2		15.3		1.3		0.1

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		289		11.3		15.1		23.8		27.7		31		30		31		31		30		30.5		19.4		8.1

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		357.3		28.5		27.7		30.7		30		31		30		31		31		30		31		29.5		26.9

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		364.9		31		28		31		30		31		30		30.9		31		30		31		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		348.8		31		28		31		30		31		28.8		24.2		23.7		29.1		31		30		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		235.1		30.7		28		30.6		27.5		22.2		5		0.1		0.3		7.5		23.7		28.6		30.9

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		107.6		22.3		20.6		15.3		5.9		1.3		---		---		---		---		4.2		14.3		23.7

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		27.1		6.3		6.1		2.3		0.1		0.3		---		---		---		---		0.1		3.8		8.1

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		1.7		0.4		---		---		---		---		---		---		---		---		---		0.3		1

PRECIPITATION

Average Precipitation

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		1013.5		144.8		99.1		96.5		73.7		68.6		38.1		20.3		25.4		40.6		94		165.1		144.8

Average Number of Days With Precipitation

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		159		20		16		17		14		10		9		5		7		8		15		18		20

Most Reported Precipitation in a Month

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		301		239		212		207		166		94		78		61		117		151		197		295		301

Least Reported Precipitation in a Month

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		---		15		9		39		14		3		4		2		---		---		8		19		35

Most Precipitation Reported in a Day

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		76.5		54.6		65.5		40.4		45.5		23.4		21.6		18.8		26.4		46.7		28.7		76.5		40.6

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

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		91		13		10		10		6		4		4		2		3		4		9		13		13

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

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		20		4		3		2		1		---		---		---		---		1		2		4		3

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

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		4		1		1		---		---		---		---		---		---		---		---		1		1

PRECIPITATION - SNOW

Average Snowfall

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		45.7		11.7		4.8		3.3		---		---		---		---		---		---		---		2.3		23.6

Most Snow Reported in a Month

Years on Record: 18

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		353.6		66		27.7		32		---		---		---		---		---		---		---		23.1		353.6

DEGREE DAYS

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		4554		705		606		558		411		276		119		34		24		123		372		578		748

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		223		---		---		---		---		5		28		85		86		19		---		---		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		2190		5		2		24		76		200		359		516		527		346		116		18		2

SKY CONDITIONS

Average Length of Day

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Hours		12.8		9.6		10.9		12.5		14.2		15.8		16.6		16.1		14.7		13		11.3		9.8		9.1

SOLAR RADIATION

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.8		4.5		7.8		11.6		16.2		18.9		20.4		22.2		19.5		14.9		8.7		5		3.7

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		6		2.7		4.1		6		7.6		9		9.5		9.2		8		6.6		4.4		3		2.3

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14		7.5		11.7		14.2		16.9		17.4		17.7		19.7		19.5		17.4		11.9		8.1		6.7

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.6		6.8		10.5		12.3		15.7		16.7		17.9		21.5		20.3		16.7		11.1		7.1		6

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.8		4.5		7.8		11.6		16.2		18.9		20.4		22.2		19.5		14.9		8.7		5		3.7

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		6.5		3.1		4.5		6.5		7.7		9.1		9.7		10.3		8.3		7.2		5.2		3.4		2.6

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		17.1		9.4		14.2		17.8		20.8		21.2		20.7		24		22		20.5		15.6		10.5		7.9

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		17.6		8.6		12.6		16.7		21.9		23.8		24		27.8		24.1		20.6		15.2		9.4		7.2

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		10.8		3.8		6		10.5		13.9		16.8		17.1		17.3		17.3		12.2		7.1		4.2		3.2

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.8		2.5		3.5		5.8		7.5		8.8		9.4		9.1		7.9		6.1		3.8		2.6		2.1

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		11.6		6.2		8.6		12.5		14.2		15.3		14.9		15.3		17.1		13.9		9.4		6.5		5.3

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		5.4		7.4		10.4		11.4		13		12.2		13.2		16.3		12.4		8.4		5.5		4.7

NEARBY - MAP

NEARBY - LIST

Bellevue, Washington (4 mi / 7 km)
Sea-Tac, Washington (5 mi / 9 km)
Seahurst, Washington (6 mi / 11 km)
Medina, Washington (8 mi / 12 km)
Seattle, Washington (8 mi / 12 km)

GEOBA.SE

Mercer Island, Washington