Peoria, Ill. — A cold overnight shift in central Illinois is expected to bring temperatures down into the mid to upper 30s late Friday, raising the risk of frost that could harm crops and backyard plants between 1 a.m. and 7 a.m. Saturday. The alert covers a wide stretch of the region, including Peoria, Galesburg, Springfield, Bloomington, and Champaign.
According to the National Weather Service office in Lincoln, conditions are becoming favorable for frost development as skies partially clear and winds calm overnight. Forecasters estimate a 30 to 50 percent chance of frost, especially in areas north of a line from Beardstown to Paris.
The biggest concern lies in low-lying and rural areas where cold air tends to settle. In these spots, temperatures could briefly fall closer to freezing — around 32 to 36 degrees — increasing the likelihood of frost forming quickly before sunrise. Fields near rivers, valleys, and open farmland are particularly vulnerable.
This sudden drop follows a stretch of milder weather across the Midwest, catching many early-season growers off guard. Tender plants, newly planted crops, and blooming vegetation are at the highest risk of damage during this window.
While the cold snap is not expected to create major travel hazards, early morning drivers along I-55 and I-74 may notice patchy ground fog, especially near river crossings and rural low spots around Springfield and Peoria. Visibility could briefly drop in these areas before sunrise.
Residents are advised to take simple precautions Friday evening. Cover sensitive plants with cloth or frost blankets, bring potted plants indoors, and ensure irrigation lines or outdoor hoses are protected from the cold. Even a few hours of frost exposure can damage or kill delicate vegetation.
The most critical period remains between 1 a.m. and 7 a.m. Saturday, when temperatures are expected to reach their lowest point and frost formation is most likely. Officials say conditions will improve after sunrise as temperatures gradually warm.
Further updates may be issued if conditions change, but for now, central Illinois residents are urged to prepare for a chilly start to the weekend.
