Porvoo is a place where safety is highly regarded. It is a peaceful and secure city, with very low crime rates. People are generally friendly and respectful, and incidents involving tourists, especially female travelers, are extremely rare. You can typically expect to feel safe walking around the city, even at night. Keep in mind, like anywhere, it's always a good idea to stay aware of your surroundings and use common sense. But overall, Porvoo should provide a secured and welcoming environment for solo female travelers.