Grundy County, Illinois
|Grundy County, Illinois|
Location in the state of Illinois
Illinois's location in the U.S.
|Founded||February 17, 1841|
430.45 sq mi (1,115 km²)
418.04 sq mi (1,083 km²)
12.40 sq mi (32 km²), 2.88%
119/sq mi (46/km²)
|Time zone||Central: UTC-6/-5|
Grundy County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 50,063, which is an increase of 33.4% from 37,535 in 2000. Its county seat is Morris. The center of population of Illinois is located in Grundy County, just northeast of the Village of Mazon. This county is part of the Chicago metropolitan area. Illinois' State Fossil, the unique and bizarre Tully Monster was first found in Mazon Creek. Grundy County Speedway is located in Morris.
According to the 2010 census, the county has a total area of 430.45 square miles (1,114.9 km2), of which 418.04 square miles (1,082.7 km2) (or 97.12%) is land and 12.40 square miles (32.1 km2) (or 2.88%) is water.
Major highways 
Adjacent counties 
Political subdivisions 
Grundy County is divided into seventeen townships:
|UVa Census Browser 1830-1840
Illinois Counties 1900-1990
As of the U.S. Census of 2000, there were 37,535 people, 14,293 households, and 10,276 families residing in the county. The population density was 89 people per square mile (35/km²). There were 15,040 housing units at an average density of 36 per square mile (14/km²). The racial makeup of the county was 97.09% White, 0.19% Black or African American, 0.24% Native American, 0.30% Asian, 0.01% Pacific Islander, 1.30% from other races, and 0.87% from two or more races. 4.13% of the population were Hispanic or Latino of any race. 20.7% were of German, 15.2% Irish, 12.0% Italian, 8.3% Norwegian, 7.4% English and 6.7% American ancestry according to Census 2000. 95.2% spoke English and 3.7% Spanish as their first language.
There were 14,293 households out of which 35.30% had children under the age of 18 living with them, 59.60% were married couples living together, 8.60% had a female householder with no husband present, and 28.10% were non-families. 23.50% of all households were made up of individuals and 9.40% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.09.
In the county the population was spread out with 26.60% under the age of 18, 8.30% from 18 to 24, 30.20% from 25 to 44, 22.50% from 45 to 64, and 12.30% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 98.90 males. For every 100 females age 18 and over, there were 97.40 males.
The median income for a home in the county is $51,719, and the median income for a family was $60,862. Males had a median income of $46,392 versus $26,487 for females. The per capita income for the county was $22,591. About 3.20% of families and 4.80% of the population were below the poverty line, including 5.00% of those under age 18 and 6.00% of those age 65 or over.
Climate and weather 
|Climate chart (explanation)|
In recent years, average temperatures in the county seat of Morris have ranged from a low of 13 °F (−11 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −24 °F (−31 °C) was recorded in January 1985 and a record high of 103 °F (39 °C) was recorded in June 1988. Average monthly precipitation ranged from 1.59 inches (40 mm) in February to 4.16 inches (106 mm) in June.
See also 
- "Grundy County QuickFacts". United States Census Bureau. Retrieved 2011-11-05.
- "Find a County". National Association of Counties. Retrieved June 7, 2011.
- Population and Population Centers by State, 2010
- "Census 2010 U.S. Gazetteer Files: Counties". United States Census. Retrieved 2011-11-05.
- Historial Census Browser, University of Virginia, Geospacial and Statistical Data Center, 2004
- Illinois Counties 1900-1990, U.S. Census Bureau
- "American FactFinder". United States Census Bureau. Retrieved January 31, 2008.
- Adams, James N. (compiler) (1989), Keller, William E., ed., Illinois Place Names, Springfield: Illinois State Historical Society, p. 581, ISBN 0-912226-24-2
- "Monthly Averages for Morris, Illinois". The Weather Channel. Retrieved 2011-01-27.
|LaSalle County||Will County|
|Livingston County||Kankakee County|