Illinois (IL) lies in the American Midwest, its diversified economy relying on industry, agriculture and financial services. The capital of Illinois is Springfield, but the largest and most famous city is Chicago. It was in Chicago that the world’s first skyscraper opened in 1885; the Home Insurance Building was 10 stories when it opened (two were later added) and measured 138.0 ft.
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Table of Contents
Quick Facts
Name Illinois Abbreviation IL Capital Springfield Largest city Chicago (Population: 2 664 452) Current time 10:52 Time zone CST (UTC-6), the state observes daylight saving time CDT (UTC-5) Population 12,813,469 (#6 most populous US state) Area 57,914 mi² (#25 largest US state) Admitted to the Union December 3, 1818 (#21 state to join) ⭐ Capital of Illinois
The capital of Illinois is Springfield, which was founded in 1821 and was initially named Calhoun in honor of South Carolina Senator John Caldwell Calhoun. Springfield became the capital of Illinois in 1839.
🏙️ Largest City in Illinois
The largest city in Illinois is Chicago, with a population of 2,664,452 in 2023. Aurora comes in second with a population of 177,563 and Joliet comes in third with 150,489.
🕒 Time in Illinois
The current time in Chicago is [timezone=”America/Chicago” format=”G:i”]. The entire state of Illinois observes Central Standard Time (CST, UTC-6), and from March to November it transitions to Daylight Saving Time CDT (UTC-5).
🧑🤝🧑 Population of Illinois
In 2023, Illinois had a population of 12,813,469, making it the 6th most populous state in the USA.
📍 Area of Illinois
The total area of Illinois is 57,914 mi², of which 55,586 mi² is land and 2,309 mi² is water. Illinois is the 25th largest US state.
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Fun Facts About Illinois
🧩 Illinois Neighboring States
Illinois has land borders with five US states. It has Missouri to the southwest, Iowa to the northwest, Wisconsin to the north, Indiana to the east, and Kentucky to the south. In addition, its borders form a shoreline with Lake Michigan, where Illinois has a water border with the state of Michigan. Also of note is the enclave of Kaskaskia, a small territory surrounded by the state of Missouri.
📅 Date of Illinois Statehood
Illinois entered the Union on December 3, 1818 as the 21st state in the order, its predecessor being the Territory of Illinois.
📛 Nickname of the State of Illinois
Illinois is proud of the 16th President of the United States, Abraham Lincoln, who lived in the state for many years. Thus, he chose the official slogan “Land of Lincoln”, which he uses, among other things, on car license plates.
The unofficial nickname of Illinois is “The Prairie State”, referring to the vast prairie plains that characterize the state.
⛰️ Highest Mountain in Illinois
With only 1,235 ft, the highest mountain in Illinois is Charles Mound, which lies near the state’s border with Wisconsin.
🏞️ Rivers in Illinois
The longest river in Illinois is the Mississippi River with the total length of flow in all states 2,318 mi. This is followed by the Ohio River (981 mi), the Wabash River (503 mi), the Illinois River (332 mi), and the Rock River (299 mi).
🎓 Universities in Illinois
The largest university in the state is the University of Illinois Urbana-Champaign, which was founded in 1867 and is attended by around 57,000 students. In second place is the University of Illinois Chicago with around 34 thousand students and in third place is Northwestern University with around 23 thousand enrolled students.
✉️ Illinois ZIP Codes
The state of Illinois has dedicated zip codes in the 600xx-620xx and 622xx-629xx ranges. For more information, see the article ZIP Codes in the USA You can look up the ZIP code for a specific address on the United States Postal Service website.
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Weather in Illinois
The best time of year to visit Illinois is autumn, when temperatures are pleasant and rainfall is lower than in spring and summer.
Spring in Illinois brings a gradual improvement in the weather, with temperatures usually between 50°F and 68°F. Frequent rain is to be expected, especially in April and May, and occasional thunderstorms may be accompanied by strong winds and hail.
Summers in Illinois are hot and humid, with temperatures usually reaching 77°F to 86°F. Higher humidity and, especially in June, frequent rain showers can be unpleasant and can cause flash floods.
Fall in Illinois is more pleasant, with normal temperatures ranging from 50°F to 59°F. Rainfall is less frequent compared to other months, which creates favorable conditions for traveling and exploring the countryside.
Winters in Illinois are very cold, with temperatures dropping below freezing at 32°F to 14°F. Snowfall is common, with snowfall in January and February up to 30 cm per month. The sensible temperature can be further reduced by strong winds.
🌡️ Average Temperatures and Precipitation in Illinois
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Things to Do in Illinois
1️⃣ Millennium Park in Chicago
Millennium Park is one of the most famous attractions in the entire state, attracting millions of visitors each year. The park is known for its art installations, the most popular of which is the stainless steel bean Cloud Gate. Photos of the mirrored skyscrapers are one of Chicago’s hallmarks. The free park is often the site of various outdoor cultural and social events.
2️⃣ Six Flags Great America Amusement Park
Six Flags Great America is one of the best theme parks in the USA. Visitors can enjoy around a hundred attractions, more than ten of which are thrill rides. On hot summer days, the adjacent Hurricane Harbor Water World is popular, bringing welcome refreshment. The park offers all-day fun for families and groups of friends.
3️⃣ Chicago’s Willis Tower
The Willis Tower is a 1,450 ft tall skyscraper in Chicago, which until 2009 was known as the Sears Tower after the retail company that built it in the 1970s. Visitors to the skyscraper can access the Skydeck platform on the 103rd floor, which offers fabulous views of the city and surrounding landscape.
In good visibility, you can see as far as 50 mi. A popular attraction in the skyscraper is The Ledge, an extended balcony with a glass floor through which you can look directly down onto the street.
4️⃣ Route 66 Museum
The famous Route 66, which ran through eight American states including Illinois, is the subject of a museum in Pontiac. The museum is home to an extensive collection of photographs, artifacts and other memorabilia about the history of this legendary highway. Visitors can learn how Route 66 has influenced American culture and view the historic vehicles that once traveled the route.
5️⃣ Chicago Museum of Science and Industry
The Chicago Museum of Science and Industry is one of the largest of its kind in the world. Visitors to the museum can explore interactive exhibits focused on science, technology and industry. A popular exhibit is the German submarine U-505, which has belonged to the museum’s collection since 1954. Some of the museum’s exhibits are continuously renewed, and regular workshops are also held.
6️⃣ Magnificent Mile Shopping Boulevard
If New York has the famous Fifth Avenue, Chicago has the Magnificent Mile. The famous downtown street is lined with luxury shops and designer boutiques, complemented by expensive restaurants and hotels.
Some of the buildings are architecturally interesting in their own right. The Tribune Tower, a neo-Gothic skyscraper dating from 1923, or the Wrigley Building, home to the famous bubblegum manufacturer, are examples.
7️⃣ Shedd Aquarium in Chicago
Home to thousands of species of marine and freshwater animals, the Shedd Aquarium in Chicago is one of the largest aquatic worlds in the United States. Dolphins, sharks, penguins, turtles and other creatures from the oceans, rivers and lakes can be seen behind the aquarium’s thick glass. The aquarium features interactive exhibits and educational programs focused on marine life conservation. The Shedd Aquarium is a fun place for families with young and old children.
8️⃣ Navy Pier in Chicago
Formerly used as a pier for military ships, this is now a popular tourist attraction in Chicago that offers a variety of fun activities including a Ferris wheel and restaurants. During the summer season, the pier is a popular venue for concerts or theatrical performances. Visitors can enjoy boating on Lake Michigan or just enjoy the Chicago skyline in the background.
9️⃣ Illinois State Capitol Building
The Capitol Building in the state capitol in Springfield serves as the seat of government and is one of the most important historic buildings in all of Illinois. Built between 1868 and 1888, the Capitol is distinguished by its beautiful Neo-Renaissance Revival architecture with elements of the Second Empire style. If interested, a guided tour of the museum is available, which includes a visit to the meeting rooms.
🔟 The Art Institute of Chicago
The Art Institute of Chicago is one of the most important art museums in the world. Its collection includes thousands of works, many of which are Impressionist and Post-Impressionist paintings by French artist Claude Monet, Dutch painter Vincent van Gogh, and French painter Georges Seurat. Some of the museum’s exhibits are continuously renewed.
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Largest Cities in Illinois
The table below shows the ten largest cities in the state of Illinois in 2023, the source of the data is the United States Census Bureau, a federal agency whose primary function is to count the population.
City County Population 1 Chicago Cook, DuPage 2,664,452 Map of Chicago 2 Aurora DuPage, Kane, Kendall, Will 177,563 Map of Aurora 3 Joliet Will, Kendall 150,489 Map of Joliet 4 Naperville DuPage, Will 150,245 Map of Naperville 5 Rockford Winnebago, Ogle 146,120 Map of Rockford 6 Elgin Kane, Cook 113,310 Map of Elgin 7 Springfield Sangamon 112,544 Map of Springfield 8 Peoria Peoria 110,460 Map of Peoria 9 Champaign Champaign 89,189 Map of Champaign 10 Waukegan Lake 87,642 Map of Waukegan -
Sports Teams in Illinois
🏒 Ice Hockey (NHL)
The only club from Illinois in the famous NHL is the Chicago Blackhawks, the club was founded in 1926 and belongs to the Central Division in the Western Conference. It plays its home games at the United Center in Chicago, the club colors are red, white and black.
🏈 American Football (NFL)
The American Football League is played from Illinois as the only Chicago Bears, who played their first ever NFL season in 1920. The club is part of the North Division of the NFC Conference, and plays its home games at Soldier Field in Chicago. The Bears have chosen navy blue, orange and white as their club colors.
🏀 Basketball (NBA)
The only club from Illinois in the NBA is the Chicago Bulls of the Central Division in the Eastern Conference. The team plays its home games at the United Center in Chicago. The club colors are red, black, and white, and the Chicago Bulls played their first season in the NBA in 1966.
⚾ Baseball (MLB)
There are two clubs in the state of Illinois that play in the MLB baseball league.
The Chicago Cubs played in the National League as early as 1876 and are now part of its Central Division. The club colors are blue, red, and white. The Cubs play their home games at Wrigley Field in Chicago.
The other club is the Chicago White Sox, where baseball began to be played in 1901. The team belongs to the Central Division in the American League, and plays its home games at Guaranteed Rate Field in Chicago. The club colors of the White Sox are black, silver, and white.
⚽ Soccer (MLS)
The Chicago Fire FC has played in the MLS soccer league since the 1998 season, affiliated with the Eastern Conference. The club colors are red, blue, navy blue, and white, with all home games played at Soldier Field in Chicago.
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Illinois State Symbols
The State of Illinois has adopted a variety of state symbols since its admission to the Union in 1818, listed below are just a few.
State Flag of Illinois
The Illinois state flag consists of the state seal on a white background, accompanied by the state name. The current design has been in use since September 17, 1969, when the seal’s graphic design was slightly modified and the state name was added.
Great Seal of Illinois
The main motif of the seal is a bald eagle standing on a rock, holding a shield in its claws and a banner with the state motto in its beak. On the shield are thirteen stars and thirteen stripes, representing the thirteen original states of the Union. The seal was designed by former Illinois Secretary of State from 1865-1869, Sharon Tyndale.
State Flower
Since 1908, the common blue violet (Viola sororia) has been recognized by law as the official state flower, with 30 species of the plant growing across the state.
State Bird
The northern cardinal (Cardinalis cardinalis) was added to the state symbols in 1929 and became common in Illinois after 1900.
State Fish
In 1986, a law was passed that included the bluegill (Lepomis macrochirus) among the state symbols; the fish lives in waters across Illinois.
State Snack
There are about 330 farms in Illinois that grow corn for popcorn production. Since 2004, popcorn has been the official snack.
State Mineral
Fluorite has been the state’s official mineral since 1965, with the most significant deposits in southern Illinois around the town of Rosiclare and the village of Cave-In-Rock.
State Wildflower
Illinois added a wildflower to its state symbols in 2017, which is the milkweed (Asclepias spp.).
State Vegetable
In 2015, a law was passed making sweet corn the official state vegetable. The crop is commonly grown across the state.
State Snake
As of 2022, the official state symbol is the eastern milk snake (Lampropeltis triangulum triangulum); the usual length of the reddish-brown snake with white and black edging is 60 cm to 180 cm.
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