The EF-4 tornado that struck the small Illinois town of Washington on Sunday had winds reaching 190 mph at its peak, the National Weather Service reported.
Washington officials on Tuesday said 1,000 homes, up from the previously estimated 500, were impacted, and 5,500 homes remain without power.
From noon to 5 p.m., residents will be allowed to pick up personal items but must leave again. The curfew remains set at 6 p.m.
Forecasters say the tornado that destroyed Washington traveled 46.2 miles on the ground, leveling countless homes. One person was killed and at least 122 were injured.
Forecasters confirmed Tuesday the tornado initially developed over the southeast portion of East Peoria then traveled northeast, moving through Woodford County and reaching the Woodford/LaSalle County border. It finally diminished two miles east of Long Point.
At one point the tornado measured a half-mile wide, according to reports.
The EF-2 tornado that traveled through Pekin was less intense with peak winds of 120 mph. The 100-yard-wide twister traveled 2.5 miles and injured 10.
In Gifford, an EF-3 tornado had peak winds of 140 mph and traveled 24 miles, injuring six people.
Although an F4 tornado has never been reported this time of year in Illinois, NWS forecasters say there have been 30 F2 tornadoes and 8 F3 tornadoes documented in Illinois in the month of November since 1950.
NWS forecasters said wind damage from tornados across the Midwest was felt as far as New Jersey and New York City.