MOUNT WILSON - NORTHWEST, CALIFORNIA

Average Temperature

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		13.6		4.4		5.4		7.5		11.5		15		19.7		24.3		23.6		20.7		14.6		9.8		6.2

Average High Temperature

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		19		7.6		9.4		12.5		17.6		21.7		26.9		31.6		30.7		27.2		19.8		13.6		9.2

Average Low Temperature

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		8.1		1.2		1.4		2.4		5.4		8.3		12.4		17		16.4		14.3		9.6		5.9		3.2

Highest Recorded Temperature

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		41.7		20		22.2		26.7		34.4		37.2		37.8		41.7		40.6		41.1		34.4		26.1		22.8

Lowest Recorded Temperature

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-12.2		-12.2		-7.8		-7.2		-6.1		-3.3		1.1		6.1		4.4		2.8		-3.3		-6.1		-6.7

Average Number of Days Above 90F/32C

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		40.4		---		---		---		0.2		0.7		5.7		15.6		12.3		5.3		0.6		---		---

Average Number of Days Below 32F/0C

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		46.3		11.9		11		9.8		3		0.4		---		---		---		---		0.4		2.3		7.5

Average Precipitation

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		1018		182		224		152		107		18		2		1		3		14		25		117		172

Average Number of Days With Precipitation

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		39		6		6		6		5		2		---		---		1		1		2		4		6

Most Reported Precipitation in a Month

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		1226		1226		777		706		621		133		34		13		32		222		131		963		510

Least Reported Precipitation in a Month

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		---		5		---		---		---		---		---		---		---		---		---		---		---

Most Precipitation Reported in a Day

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		421.9		421.9		347.7		379		284		50.5		29.7		12.7		32.5		174		182.6		208		306.6

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

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		29		5		5		5		4		1		---		---		---		1		1		3		4

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

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		17		3		3		3		2		---		---		---		---		---		1		2		3

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

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		11		2		3		2		1		---		---		---		---		---		---		1		2

Average Snowfall

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		95.2		29		21.6		18		7.6		2		---		---		---		---		---		6.6		10.4

Most Snow Reported in a Month

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		185.4		163.8		185.4		168.9		63.5		15.2		---		---		---		---		0.5		58.4		62.2

Heating Degree Days

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1115.6		260		208.9		172.2		83.9		35		5.6		---		---		2.8		37.8		103.9		205.6

Cooling Degree Days

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		577.2		---		---		---		5.6		21.1		80.6		188.3		168.3		96.7		16.7		---		---

Growing Degree Days

Years on Record: 53

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1817.4		---		---		---		45		155		290		442.6		421.9		320		142.9		---		---

Average Length of Day

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Hours		12.6		10.6		11.4		12.4		13.5		14.4		14.9		14.6		13.8		12.8		11.7		10.8		10.4

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.3		10.9		13.9		19.2		23.9		26.6		27.7		26.1		23.9		20.4		15.9		12.3		10.2

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		4.9		3		3.9		4.7		5.7		6.5		6.8		7		6.2		5.1		4		3		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		21.2		16.7		18.8		22.6		24.2		24.1		23.9		23.1		23.1		22.5		20.8		18.3		16.3

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		24.9		19.2		20.4		25.4		28.7		30.1		30.9		28.5		27.2		25.5		23		21.4		18.9

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.3		10.9		13.9		19.2		23.9		26.6		27.7		26.1		23.9		20.4		15.9		12.3		10.2

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.8		3.6		4.6		5.9		6.7		7.8		8.2		8.2		7		5.9		4.7		3.5		3.1

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		24.2		18.9		23.5		25.7		26.4		26.1		26.4		26.2		26.5		25.4		25.7		21.1		18.9

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		30.9		22.7		27.8		30.9		33.3		35		37.9		36.4		34.7		31		31.4		25.9		23

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		16.9		8.9		11.4		15.9		21.2		23.3		24.3		22.8		21.9		18.3		14.2		10.9		8.8

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		3.8		2.6		2.9		3.7		4.7		5.4		5.3		5.3		4.7		4.1		2.7		2.4		2.2

Minimum 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		12.6		14.7		18		21.4		21.2		21.2		20.4		21.1		19.8		18		15.5		13.5

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.1		12.9		14		17.5		22.8		23.3		23.9		21.8		22.8		20.6		18.4		16.9		14.5