If you planning to travel to Mount St. Helens Forest Learning Center, Castle Rock, 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 3:55 PM. The temperature feels like 39.4 with a humidity level of 99 so dress accordingly. Cloud coverage is 71 percent with visibility at 7.8 percent. Today’s UV index is 1, don’t forget the sunscreen if you need it! Today’s winds are traveling south at a speed of 3 MPH. At the end of the day don’t miss the sunset at 12:34 AM.