If you planning to travel to Old Post Office, Grassy Butte, North Dakota, 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 12:28 PM. The temperature feels like 20.85 with a humidity level of 90 so dress accordingly. Cloud coverage is 89 percent with visibility at 6.3 percent. Today’s UV index is 2, don’t forget the sunscreen if you need it! Today’s winds are traveling east-southeast at a speed of 17 MPH. At the end of the day don’t miss the sunset at 1:23 AM.