If you planning to travel to Lake Sammamish State Park, Issaquah, 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 3:40 PM. The temperature feels like 38.95 with a humidity level of 69 so dress accordingly. Cloud coverage is 5 percent with visibility at 14.9 percent. Today’s UV index is 2, don’t forget the sunscreen if you need it! Today’s winds are traveling east at a speed of 1 MPH. At the end of the day don’t miss the sunset at 1:01 AM.