The Springfield Journal Register reports the National Weather Service sent crews Sunday to survey the hardest-hit areas, including Taylorville, 25 miles (40 kilometers) southeast of Springfield.
Assistant Fire Chief Andy Goodall spoke to reporters Saturday night after the storms raked the city of 11,000. He said at least 100 homes had major damage, including his own.
A Taylorville Memorial Hospital spokesman said 21 people, from age 9 to 97, arrived for treatment Saturday. Most were discharged within hours.
No deaths have been reported in Illinois. One death was reported in southwest Missouri early Saturday after thunderstorms there.
The National Weather Service says peak months for tornadoes in much of the Midwest are April and June.