If you planning to travel to Ameristar Casino St. Charles, St. Charles, Missouri, here is your 6-day travel weather forecast to make sure you have all the essentials needed during your stay. Start your day when the sunrises at 11:51 AM. The temperature feels like 48 with a humidity level of 56 so dress accordingly. Cloud coverage is 5 percent with visibility at 9.8 percent. Today’s UV index is 8, don’t forget the sunscreen if you need it! Today’s winds are traveling southwest at a speed of 7 MPH. At the end of the day don’t miss the sunset at 12:22 AM.