If you planning to travel to Castle Island, Boston, Massachusetts, 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 10:40 AM. The temperature feels like 54.2 with a humidity level of 81 so dress accordingly. Cloud coverage is 98 percent with visibility at 11.1 percent. Today’s UV index is 2, don’t forget the sunscreen if you need it! Today’s winds are traveling south-southeast at a speed of 7 MPH. At the end of the day don’t miss the sunset at 10:23 PM.