City of Thunder Bay. 500 Donald Street E. P.O. Box 800 Thunder Bay, ON P7C 5K4. Office Hours: Monday – Friday: 8:30 am – 4:30 pm. Quick Links: Contact Directory A-Z Serv ices Report a Problem Website Technical Issue TTY: (807) 622-2225 City Infrastructure Dispatch: (807) 625-2195. Discover more way to Connect with us.