NAPERVILLE, ILLINOIS

Average Temperature

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		50.2		22.9		27.2		37.4		50		60.3		70		74.1		72.8		65.3		53.9		40		28.1

Average High Temperature

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		60.9		31.4		36.1		47.4		61.8		73.1		82.5		86.1		84.4		77.5		65.5		48.9		35.9

Average Low Temperature

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		39.5		14.9		18.3		27.4		38.1		47.5		57.5		62.2		61.2		53.2		42.4		31.1		20.3

Highest Recorded Temperature

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		105		65		74		85		91		95		103		105		100		102		90		78		70

Lowest Recorded Temperature

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
F		-26		-26		-21		-12		4		25		32		41		38		26		14		-4		-21

Average Number of Days Above 90F/32C

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		25.7		---		---		---		0.1		1.2		6.5		9		6.7		2.2		---		---		---

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		75.2		---		---		---		0.8		4.5		15.4		24.3		19.7		7.8		2.8		---		---

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		138.9		---		---		---		5.6		14.8		28.7		30.7		28.7		22.8		7.6		---		---

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		189.4		---		0.3		3.7		15.8		27.8		30		31		31		29.3		16.4		4.3		---

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		233.5		1.7		2.7		12		24.2		30.8		30		31		31		30		27.7		11.5		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		282.9		5.3		7		23.3		29		31		30		31		31		30		30.7		25.8		8.7

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		360.9		31		28		31		30		31		29.2		28.9		30.2		29.5		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		311.9		31		28		31		30		30		18.2		10.6		14.6		26.8		30.7		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		248.8		31		28		31		28.7		19.8		4		1.3		2.3		15.3		27		29.5		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		190.4		30.7		27.7		31		19.8		4.5		---		---		---		1.3		17.6		26.9		31

Average Number of Days Below 32F/0C

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		135.3		28.5		25.3		22		8.7		1.5		---		---		---		0.3		5.3		17.1		26.6

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		67.2		19.9		18.3		7.3		0.8		---		---		---		---		---		---		4.2		16.7

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		24.7		12.5		6		---		---		---		---		---		---		---		---		---		6.3

Average Number of Days Below 0F/-17C

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		10.8		5.2		3		0.2		---		---		---		---		---		---		---		0.1		2.4

Average Precipitation

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		35.9		1.9		1.6		2.6		3.6		3.7		4		3.8		3.8		3.4		2.7		2.7		2.1

Average Number of Days With Precipitation

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		109		9		8		10		10		11		10		9		8		8		8		9		9

Most Reported Precipitation in a Month

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		15.5		5.5		5.6		6		9.4		8.3		10.7		11.9		15.5		11.2		10.9		7.2		6.1

Least Reported Precipitation in a Month

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		---		0.1		---		0.4		0.4		---		0.6		0.1		0.6		---		0.2		0.4		---

Most Precipitation Reported in a Day

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		9.2		2.9		2.8		2.6		5.6		3.8		4		9.2		6		3.4		5.6		3		3

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

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		69		5		4		6		7		7		7		6		6		5		5		6		5

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

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		24		1		1		2		2		3		3		2		3		2		2		2		1

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

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		8		---		---		---		1		1		1		1		1		1		1		1		---

Average Number of Rainy Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		107.7		8.5		7.8		9.8		10.4		10.6		9.7		8.9		8.1		7.8		7.8		8.9		8.6

Most Rain Reported in a Day

Years on Record: 102

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		9.2		2.9		1.6		3.4		5.2		3.8		4.1		9.2		6		3.1		5.6		3		3

Most Rain Reported in a Month

Years on Record: 102

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		47.9		6.6		4.1		7.3		9.4		8.3		10.7		12		15.5		11.2		10.9		7.2		6.1

Least Rain Reported in a Month

Years on Record: 102

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		23.3		0.1		---		0.4		0.4		---		0.6		0.1		0.6		---		0.2		0.6		---

Average Snowfall

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		33.4		9.5		8		5.1		1.1		---		---		---		---		---		0.2		2.5		7

Most Snow Reported in a Month

Years on Record: 113

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
in		41.1		41.1		28.5		16.8		11.5		2		---		---		---		---		5.5		24.5		40.5

Heating Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		6607		1311		1086		884		503		228		34		5		20		119		444		793		1179

Cooling Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		683		---		---		---		1		25		155		245		194		55		7		---		---

Growing Degree Days

Years on Record: 30

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
Days		2805		---		1		5		83		277		571		705		638		386		125		14		---

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
kWh/m2		3.9		1.8		2.6		3.6		4.6		5.5		6.1		6.1		5.3		4.3		3		1.8		1.5

Average Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.5		0.7		1		1.4		1.9		2.3		2.4		2.3		2		1.5		1.1		0.8		0.6

Average Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		4.3		3.2		3.9		4.4		4.7		5.1		5.3		5.5		5.3		4.9		4.1		2.9		2.9

Average Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		4.5		3.2		3.9		4.3		4.6		5.2		5.8		6.1		5.6		5.1		4.1		2.9		2.9

Maximum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.9		1.8		2.6		3.6		4.6		5.5		6.1		6.1		5.3		4.3		3		1.8		1.5

Maximum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.6		0.7		1.1		1.5		2		2.4		2.5		2.4		2.1		1.7		1.2		0.8		0.7

Maximum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		5.3		4.1		4.6		5.8		5.6		6.4		6.1		6		6		6		4.8		4.1		3.8

Maximum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		6.1		4.4		4.9		6.5		6.2		8		7.7		7.4		7		7		5.1		4.5		4.2

Minimum Daily Solar Radiation - Global

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.1		1.5		2.1		3		3.6		4.4		5.2		4.9		4.7		3.3		2.4		1.2		1.2

Minimum Daily Solar Radiation - Diffuse

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		1.3		0.7		0.9		1.2		1.8		1.9		2.1		2.1		1.8		1.3		1.1		0.7		0.6

Minimum Daily Solar Radiation - Reflected

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		3.4		2.4		2.9		3.5		3.6		4		4.5		4.3		4.6		3.6		3.1		1.7		2

Minimum Daily Solar Radiation - Direct

Years on Record: 22

		ANNUAL		JAN		FEB		MAR		APR		MAY		JUN		JUL		AUG		SEP		OCT		NOV		DEC
kWh/m2		2.9		2.2		2.6		3		2.7		3.2		4.1		3.8		4.3		3.1		2.8		1.3		1.9