RATTLESNAKE, MONTANA

Average Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		6.5		-4.9		-4.2		0.6		6.6		10.8		15.3		19.2		18.7		13.1		7.1		0.1		-4.8

Average High Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		13.4		0.9		2.1		7.4		14		17.8		22		26.6		26.7		20.7		14.6		6.5		1.6

Average Low Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-0.5		-10.8		-10.4		-6.2		-0.8		3.8		8.5		11.7		10.6		5.4		-0.6		-6.4		-11.2

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		6.5		---		---		---		---		0.1		0.1		2.6		3.5		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		46.5		---		---		0.1		0.2		1.2		4.7		16		16.6		6.7		0.9		---		---

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		105.4		---		---		1		3.6		9.6		17.3		27		26.4		14.2		6		0.3		---

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		168.2		0.5		0.4		4.3		12.3		21.2		27.5		30.6		30.4		23.8		14.1		3.1		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		231		4.7		4.5		13.1		22.6		28.1		30		31		30.9		28.5		23.3		10.4		3.9

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		288		12.6		11.7		21.7		27.9		30.6		30		31		31		29.8		28.7		19.5		13.5

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		365		31		28		31		30		31		30		31		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		357.4		31		28		31		30		31		29.6		26.2		28.7		29.9		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		310		31		28		30.8		29.8		29		20.5		11		12.4		26		30.6		30		31

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		238.2		30.4		28		30		27.3		18.5		3.1		0.3		1.6		12.8		26.2		29.2		30.9

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		177.9		27.8		26.7		26		17.2		4.4		0.1		---		---		2.5		17.3		25.8		30

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		87.6		18.7		18.8		12.1		2.2		---		---		---		---		---		2.8		12		21

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		47.9		12.9		10.1		5.7		0.6		---		---		---		---		---		0.5		5		13.1

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		23.1		8.3		3.8		2.8		---		---		---		---		---		---		0.2		2		6

Average Precipitation

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		322.6		7.6		7.6		15.2		27.9		55.9		63.5		45.7		30.5		33		20.3		10.2		10.2

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		8016		1299		1135		989		633		422		186		63		76		302		631		989		1291

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		241		---		---		---		---		4		20		108		93		17		---		---		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1727		1		---		7		37		122		289		510		484		211		60		6		---

Average Length of Day

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Hours		12.8		9.5		10.8		12.5		14.3		15.9		16.7		16.2		14.8		13		11.3		9.8		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		13.6		4.7		7.8		12.2		17.3		20.7		22.6		23.7		20.1		14.7		9.5		5.5		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		6.1		2.8		4.1		6.1		7.6		8.9		9.5		9.2		8		6.6		4.7		3.2		2.4

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		8		12.1		15.4		18.2		19		19.6		21.1		20.1		17.1		13.1		9.3		7.3

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		7.2		10.6		13.5		17.9		19.9		21.7		24		21.2		16.5		12.3		8.1		6.5

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.6		4.7		7.8		12.2		17.3		20.7		22.6		23.7		20.1		14.7		9.5		5.5		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		6.4		3		4.5		6.6		7.7		9.1		9.7		9.9		8.5		7.2		5		3.5		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		17.2		8.9		13.6		18.1		20.8		21.5		22.5		23.6		22.4		20.8		14.6		10.9		8.8

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		17.9		8.3		12.3		17.1		21.8		24.2		26.9		27.5		24.5		20.9		14		9.7		8

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		11.3		4		6		10.5		15.3		16.6		19.1		17.9		18.4		11.2		8.4		4.4		3.4

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.8		2.5		3.4		5.8		7.5		8.8		9.4		9.1		7.9		6		4.4		2.7		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		12.3		6.7		8.9		12.9		15.8		15.1		16.6		15.9		18.2		12.5		11.5		7		6

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		10.9		5.8		7.3		10.4		14		12.6		15.6		14.3		18.4		10.6		10.6		5.9		5.2