WEST YELLOWSTONE, MONTANA

Average Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		2.8		-7.8		-7.9		-3.5		2.6		7.7		11.4		15.5		14.9		10.1		3.6		-3.8		-9.4

Average High Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		11.4		-1.4		0.3		5		11.3		16.3		20.6		26.5		26.1		20.6		11.5		2.3		-2.8

Average Low Temperature

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-5.8		-14.2		-16.1		-12		-6.2		-1		2.1		4.4		3.7		-0.3		-4.3		-10		-16

Highest Recorded Temperature

Years on Record: 51

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		36		8		13		19		26		31		33		36		35		33		28		20		13

Lowest Recorded Temperature

Years on Record: 51

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-54		-50		-54		-41		-32		---		-8		-6		-12		-22		-30		-38		-50

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		3		---		---		---		---		---		---		1.6		0.8		0.6		---		---		---

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		38.4		---		---		---		0.4		1		1.8		15.2		15.2		4.2		0.5		---		---

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		94.2		---		---		---		0.4		7.7		13.4		29.4		27.6		13.2		2.5		---		---

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		142.9		---		---		---		4.3		16		27.1		31		30.7		26.1		7.6		---		---

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		186.3		---		---		1.6		19.1		26.5		30		31		31		29		17		1.1		---

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		239.6		0.4		1		18.9		28.4		31		30		31		31		29.7		27.2		10.4		0.5

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		365		31		28		31		30		31		30		31		31		30		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		361.5		31		28		31		30		31		30		28.9		29.9		29.7		31		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		331.1		31		28		31		30		29.6		26.1		16.8		20.1		26.7		30.7		30		31

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		247.8		31		28		31		26.9		19		5.3		2.1		2.9		15		26.4		29.2		31

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		150.9		27.1		25.9		26.3		12.7		2.1		---		---		---		0.7		9		20.9		26.3

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		87.6		18.5		20.2		15.2		2.7		---		---		---		---		---		1.6		9.9		19.4

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		38.2		8.9		11.4		3.2		---		---		---		---		---		---		---		2.9		11.8

Average Precipitation

Years on Record: 47

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		510		50		40		40		30		50		50		30		30		30		30		40		40

Average Number of Rainy Days

Years on Record: 47

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		46		4		4		4		3		4		4		3		2		2		3		3		4

Average Snowfall

Years on Record: 45

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		363		76		59		57		24		10		2		---		---		3		16		46		66

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		10219		1457		1323		1218		853		597		377		179		201		446		823		1199		1546

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		31		---		---		---		---		---		---		19		10		2		---		---		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		827		---		---		---		6		45		106		305		279		79		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		9.8		11		12.5		14.1		15.4		16.1		15.7		14.5		13		11.4		10.1		9.4

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14.5		6.2		9.7		14		17.7		20.4		22.8		24.1		21		16.1		10.7		6.8		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		4.9		2.1		3		4.5		6.4		7.9		8.3		7.4		6.3		4.9		3.6		2.4		1.8

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		17.4		13.3		16.3		18.6		18.7		18.8		19.7		21.4		21		19.4		16.1		13.2		11.6

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.3		13.9		17.4		19.6		20		20.4		23		26.9		24.9		21.6		17.1		13.8		13.3

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		6.2		9.7		14		17.7		20.4		22.8		24.1		21		16.1		10.7		6.8		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		5.3		2.2		3.3		5		6.8		8.3		8.9		8.5		6.9		5.6		3.8		2.5		1.9

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.9		14.9		18		20.6		22.5		21.9		22.8		24.3		22.9		22.1		20.2		15.9		13.5

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		24.1		15.9		19.8		23.3		27.1		27.2		30.5		34		28.8		26.4		22.9		17.4		16

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.7		5.8		8.5		11.8		16		18.3		19.7		19.6		19.1		13.2		9.4		5.9		4.8

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		4.3		2		2.8		4.1		5.4		7.1		7.3		6.2		5.7		4.3		3		2.1		1.6

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14.8		11.9		13.8		15.2		16.7		16.8		17.2		17.4		19		15.1		13.6		10.8		9.8

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		14.9		12		13.8		14.2		16.3		16.4		17.3		17.9		20.9		14.6		13.5		10.8		10.7