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 12:10 PM. The temperature feels like 10.5 with a humidity level of 58 so dress accordingly. Cloud coverage is 36 percent with visibility at 14.5 percent. Today’s UV index is 0, don’t forget the sunscreen if you need it! Today’s winds are traveling west-southwest at a speed of 6 MPH. At the end of the day don’t miss the sunset at 9:12 PM.