A cool, quiet morning settles over central Illinois, but the bigger concern builds after sunset as temperatures drop fast, setting up a frost risk that could damage plants and create slick early travel conditions.
According to the National Weather Service, patchy frost is expected late tonight into early Saturday across Champaign, Decatur, Bloomington, and Danville, with temperatures falling into the mid-30s by daybreak.
This is part of a broader system pulling colder-than-average air across the Midwest, keeping early May conditions unusually brisk before a quick rebound.
Skies stay mostly sunny through the afternoon, helping temperatures reach the upper 50s. By evening, clearing skies and light winds allow rapid cooling. Frost is most likely in low-lying and rural areas, especially north of I-70, where cold air settles quickly in open fields and along drainage areas.
The primary impact targets vegetation. Early gardens, flowering trees, and sensitive crops face damage if left unprotected. Urban areas like Champaign may stay slightly warmer, but surrounding communities such as Mahomet and Monticello carry a higher frost risk.
Drivers should also remain alert early Saturday. Any lingering moisture on bridges and overpasses along I-57 and I-74 could briefly freeze, creating isolated slick spots before sunrise.
Looking ahead, a quick warm-up begins. Saturday afternoon turns milder with highs near the upper 50s, followed by a stronger push into the upper 60s Sunday. By Monday and Tuesday, temperatures climb into the 70s with increasing chances for showers and thunderstorms. A few storms could bring gusty winds, though severe risk remains limited for now.
Five-day outlook:
Saturday: Early frost, then partly sunny, high near 58°F
Sunday: Warmer, high near 67°F
Monday: Chance of storms, high near 75°F
Tuesday: Showers likely, high near 65°F
Wednesday: Cooler, high near 60°F
