If you planning to travel to Fort Constitution Historical Site, New Castle, New Hampshire, 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 11:44 AM. The temperature feels like 41.2 with a humidity level of 77 so dress accordingly. Cloud coverage is 73 percent with visibility at 10.6 percent. Today’s UV index is 0, don’t forget the sunscreen if you need it! Today’s winds are traveling northwest at a speed of 14 MPH. At the end of the day don’t miss the sunset at 9:11 PM.