 Big Z weather is a service of Alton Auto Butler. Become a member today. Wash every day at one low price. Alton Auto Butler, where every car gets the royal treatment. Tonight we will have temperatures in the low mid 50s and in the morning cloudy skies that will continue throughout the day. A high near 80 degrees on Monday night. We're in the lower 60s and on Tuesday we'll wake up to sunshine.