The victim was identified Friday as 69-year-old Jacklyn K. Klosa. Authorities say her body was found during "a secondary search."
Officials earlier in the day identified the first victim as 67-year-old Geraldine M. Schultz.
Roughly a dozen other people were injured Thursday after at least one tornado swept through tiny Fairdale, a small farming community of about 150 people that was among the hardest-hit areas. Fairdale is an unincorporated town of about 150, about 80 miles northwest of Chicago.
The National Weather Service says at least two tornadoes swept across six north-central Illinois counties. Three teams were out to assess damage.