If you planning to travel to Lake Sylvia State Park, Montesano, Washington, 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 3:03 PM. The temperature feels like 48.45 with a humidity level of 98 so dress accordingly. Cloud coverage is 87 percent with visibility at 8 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 9 MPH. At the end of the day don’t miss the sunset at 1:51 AM.