 Big Z weather is a service of Alton Auto Butler. Revitalize your ride with the area's most trusted full-service car wash and express detail. Alton Auto Butler, where every vehicle gets the royal treatment. Today, look for sunshine high in the upper 80s. The northeast wind around 5 to 10 miles per hour. Partly cloudy tonight, low in the upper 60s. On Friday, mostly sunny in the morning, then increasing clouds by the afternoon. Slight chance of showers and storms.