If you planning to travel to 9-11 Memorial, O'Fallon, 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 12:43 PM. The temperature feels like 46.5 with a humidity level of 89 so dress accordingly. Cloud coverage is 78 percent with visibility at 8.2 percent. Today’s UV index is 0, don’t forget the sunscreen if you need it! Today’s winds are traveling south-southeast at a speed of 7 MPH. At the end of the day don’t miss the sunset at 10:51 PM.