ALTON, IOWA

Average Temperature

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		8.5		-8.1		-5.8		1.1		8.8		15.2		20.6		23.6		22.3		17.4		10.6		1.9		-5.4

Average High Temperature

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		14.8		-2.5		-0.1		6.9		15.6		22.1		27.1		30.4		29		24.1		17.4		7.7		-0.1

Average Low Temperature

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		2.2		-13.6		-11.4		-4.7		1.9		8.3		14		16.7		15.6		10.8		3.8		-3.8		-10.7

Highest Recorded Temperature

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		43.3		18.9		18.3		30.6		35		41.1		40		43.3		41.7		37.8		33.9		25.6		17.2

Lowest Recorded Temperature

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
C		-41.1		-41.1		-36.7		-28.9		-22.8		-6.1		---		4.4		0.6		-6.7		-23.3		-24.4		-36.7

Average Number of Days Above 90F/32C

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		29.4		---		---		---		0.1		1.6		6		11.2		7.7		2.7		0.1		---		---

Average Number of Days Below 32F/0C

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		160.5		30.6		27.5		25.3		12		2.2		---		---		---		1.1		8.4		23.4		30

Average Number of Days Below 0F/-17C

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		25.3		10.3		6.7		1.2		---		---		---		---		---		---		---		0.6		6.5

Average Precipitation

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		665		17		19		39		60		88		101		86		87		75		45		28		20

Average Number of Days With Precipitation

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		83		5		4		6		8		10		10		8		9		8		6		5		4

Most Reported Precipitation in a Month

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		266		67		79		133		184		224		234		209		227		266		151		101		80

Least Reported Precipitation in a Month

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		---		---		---		---		9		8		14		6		8		12		---		---		---

Most Precipitation Reported in a Day

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
mm		145.5		34.5		41.1		65.5		49.8		90.9		84.3		88.1		137.7		145.5		81		51.8		36.6

Avg. No. of Days w/Precip. Above 0.1in/2.5mm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		55		2.1		1.9		4.4		6		7.2		6.9		5.3		5.5		5.6		4.4		3.3		2.4

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

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		53		3		2		4		5		7		7		5		6		5		4		3		2

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

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		16		---		---		1		2		2		3		2		2		2		1		1		---

Avg. No. of Days w/Precip. Above 0.5in/13mm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		18.3		0.4		0.2		1.1		2.1		2.4		2.9		2.4		2.1		2.1		1.4		0.9		0.3

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

Years on Record: 105

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

Average Snowfall

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		76.2		16.5		14		16.3		4.3		0.5		---		---		---		---		1.8		7.9		15

Average Number of Days With Snow

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		17.1		4.2		2.9		2.6		0.9		---		---		---		---		---		0.3		2.4		3.8

Most Snow Reported in a Month

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
cm		61		61		59.2		50.5		31.8		15.2		---		---		---		5.1		20.3		43.2		43.7

Avg. No. of Days w/Snow Above 1in/2.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		10.3		2.3		1.5		1.8		0.7		---		---		---		---		---		0.1		1.4		2.5

Avg. No. of Days w/Snow Above 3in/7.5cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		3.1		0.8		0.4		0.7		0.2		---		---		---		---		---		---		0.2		0.8

Avg. No. of Days w/Snow Above 5in/12.7cm

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		0.8		0.3		0.1		0.2		---		---		---		---		---		---		---		0.1		0.1

Heating Degree Days

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		2732.2		646.1		523.9		365		145		33.3		1.7		---		---		16.7		110.6		326.7		563.3

Cooling Degree Days

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		476.1		---		---		---		2.8		27.2		94.4		165		131.1		50.6		5		---		---

Growing Degree Days

Years on Record: 105

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		1519.9		---		---		---		---		160.2		316.7		420.2		380.6		223.3		18.9		---		---

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		11.1		12.5		14		15.2		15.9		15.5		14.4		12.9		11.5		10.2		9.6

Average Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.8		6.3		9.2		12.6		16.4		19.7		22		22.3		19.3		15.1		10.8		6.8		5.5

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		2.4		3.5		5.1		6.8		8.1		8.6		8		7		5.5		3.8		2.7		2.1

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		15.9		12.1		14		15.6		17		18.1		19.1		19.8		19		17.4		15.4		11.8		11.2

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		16.5		12.3		14.2		15		16.5		18.6		21.2		22.6		20.4		18		15.9		12.2		11.5

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		13.8		6.3		9.2		12.6		16.4		19.7		22		22.3		19.3		15.1		10.8		6.8		5.5

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		5.6		2.5		3.6		5.3		7.1		8.5		9		8.7		7.5		5.9		4.2		2.8		2.2

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		19.2		14.4		17.6		19		21.1		21.3		22.3		21.7		21.1		21.3		19.8		16.2		14.4

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		22.1		15.3		19.1		20.6		23.9		25.3		28.7		26.9		24.5		24.5		22.2		18.4		15.6

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		5.7		6.7		9		13.2		15.6		18.6		16.9		16.9		11.1		8.3		5.6		4.6

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		4.8		2.3		3.1		4.6		6		7.4		7.5		7.4		6.5		4.7		3.3		2.3		1.9

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		12.1		10.3		9		10.2		13.3		14.3		16.3		15.1		16.5		12.1		10.8		8.9		8.5

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Mj/m2		10.6		10		7.6		7.7		10.7		11.5		15.1		12.9		15.7		9.9		9.5		8.2		8