If you planning to travel to Old Post Office, St Louis, 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 12:51 PM. The temperature feels like 50.55 with a humidity level of 72 so dress accordingly. Cloud coverage is 41 percent with visibility at 13.5 percent. Today’s UV index is 0, don’t forget the sunscreen if you need it! Today’s winds are traveling south at a speed of 10 MPH. At the end of the day don’t miss the sunset at 10:41 PM.