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 12:06 PM. The temperature feels like 6.15 with a humidity level of 48 so dress accordingly. Cloud coverage is 57 percent with visibility at 14.9 percent. Today’s UV index is 0, don’t forget the sunscreen if you need it! Today’s winds are traveling west at a speed of 7 MPH. At the end of the day don’t miss the sunset at 9:42 PM.