If you planning to travel to William O'Brien State Park, Marine on St. Croix, Minnesota, 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 10:53 AM. The temperature feels like 64.7 with a humidity level of 48 so dress accordingly. Cloud coverage is 5 percent with visibility at 14.7 percent. Today’s UV index is 7, don’t forget the sunscreen if you need it! Today’s winds are traveling west at a speed of 3 MPH. At the end of the day don’t miss the sunset at 1:24 AM.