Champaign, Illinois — Patchy frost is expected to form overnight Sunday into early Monday across eastern parts of central Illinois, with temperatures dropping to 37 to 42 degrees between 2 a.m. and 6 a.m., threatening early-season crops and exposing outdoor workers to cold conditions in cities including Champaign, Danville and Mattoon.
According to the National Weather Service in Lincoln, the frost risk will be most concentrated east of Interstate 57, including Champaign and areas toward the Indiana border, where clear skies and light winds will allow temperatures to fall quickly before sunrise Monday.
The cold snap is part of a broader system that will shift quickly into a storm pattern by Sunday afternoon. Showers and thunderstorms are expected to develop between 2 p.m. and 7 p.m. Sunday across Springfield, Peoria and Bloomington, creating slick roads, reduced visibility and ponding water on low-lying streets and underpasses, especially along I-55 and I-74.
Storm chances intensify Sunday night into Monday night, with a 60 to 70 percent likelihood of thunderstorms between 6 p.m. and 10 p.m. Monday. Stronger storms may produce gusty winds capable of downing tree limbs and causing isolated power outages, particularly in Decatur and Springfield.
Drivers should avoid water-covered roads and slow down during heavy rain, while residents are urged to secure outdoor items ahead of gusty winds.
Frost conditions will peak between 2 a.m. and 6 a.m. Monday, and sensitive vegetation should be protected before temperatures drop.
