CHATHAM, MASSACHUSETTS

Average Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		10.4		-0.6		0.4		3.4		7.6		12.8		18.1		21.7		21		17.5		12.1		7.5		2.7

Average High Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		14.5		3.6		4.6		7.6		11.4		16.9		22.4		25.9		25.2		21.4		16.4		11.5		6.6

Average Low Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		6.3		-4.6		-3.8		-0.8		3.6		8.7		13.8		17.4		16.9		13.6		7.8		3.4		-1.3

Highest Recorded Temperature

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		36		15		15		18		26		28		36		34		33		31		27		23		18

Lowest Recorded Temperature

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-22		-21		-22		-16		-7		---		5		10		10		2		-1		-9		-18

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		---		---		---		---		---		---		0.7		0.2		---		---		---		---

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		28.1		---		---		---		0.1		0.4		4.3		13		9.2		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		100.9		---		---		---		0.2		4.5		19.4		29.2		28.3		16.4		2.8		0.1		---

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		169.3		---		---		0.5		3.8		19.7		28.8		31		31		29.5		19.3		5.2		0.6

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		241.8		2.9		2.4		8.3		20		29.9		30		31		31		30		30.1		19.4		6.8

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		316.2		13.7		14.6		24.9		29.1		31		30		31		31		30		31		28.8		21.1

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		360.7		31		28		31		30		31		30		29.2		28.8		29.7		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		301.4		31		28		31		30		31		21.3		7.1		9.7		21.2		30.1		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		228.1		31		28		31		29.6		20.6		2.7		---		0.1		5.2		21.6		27.6		30.7

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		160.3		30.1		27.6		29.2		18.6		2.5		---		---		---		0.2		6.9		17.8		27.5

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		97.3		24.6		23		17.3		3.9		0.1		---		---		---		---		0.7		7.8		19.7

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		23.6		10.9		6.6		2.2		---		---		---		---		---		---		---		0.2		3.6

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		3.2		2.6		0.5		---		---		---		---		---		---		---		---		---		0.1

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
mm		1219.2		99.1		94		119.4		111.8		94		91.4		83.8		96.5		99.1		101.6		116.8		114.3

Average Number of Rainy Days

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		71		7		7		6		6		5		4		5		6		5		4		6		6

Average Snowfall

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		91		22		19		27		3		---		---		---		---		---		---		---		18

Average Relative Humidity

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
%		77		75		74		73		74		76		77		78		80		80		79		77		75

Average Dew Point

Years on Record: 12

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		5		-4		-4		-2		2		7		13		17		16		13		8		3		-2

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		5681		1052		904		834		584		312		78		5		10		90		351		587		874

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		468		---		---		---		---		4		64		191		160		45		4		---		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		2494		---		---		---		21		175		437		651		615		406		151		35		4

Average Length of Day

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Hours		12.7		10.1		11.1		12.5		13.9		15.1		15.7		15.4		14.3		12.9		11.5		10.3		9.7

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14.5		5.9		9.4		13.7		18		21.1		22.6		22.8		20.6		16.4		11.7		7		5.4

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.3		2.6		3.6		5.1		6.7		7.9		8.5		7.9		6.7		5.3		3.8		2.8		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		16.3		10		13.6		16.9		18.6		19.4		19.6		20.3		20.3		19.1		16.9		11.6		9.9

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		17.5		9.9		14		17.1		19.3		20.9		22		23.4		22.8		20.7		17.8		11.9		10.2

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14.5		5.9		9.4		13.7		18		21.1		22.6		22.8		20.6		16.4		11.7		7		5.4

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.7		2.7		3.8		5.4		7.2		8.4		9		8.6		7.3		5.9		4.2		3		2.3

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.4		12.1		18.2		20.1		23.1		22.1		21.8		23		23.4		22.1		19.8		14.4		12.1

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		22.8		12.2		20.8		22.1		27.9		26.9		27.1		29.9		29.2		25.9		22.2		15.8		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		12.2		5		6.5		11.9		14.7		18.1		19.7		19.9		18.2		13.2		10.1		5.1		4

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		4.6		2.6		3		4.5		5.5		7.1		7.8		6.9		5.7		4.6		3.4		2.6		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		13		7.9		8.3		14.1		14.8		16.6		17.2		17.8		17.8		14.6		13.8		7.4		6.3

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.2		7.3		6.9		12.9		12.7		15.4		16.7		17.8		17.9		13.4		13.4		6.4		5.5