13 Septemba bu ubochi nke 13th (nke iri na atọ) na onwa ana kpo Septemba. Na Gregorian calender, 13 Septemba bu ubochi nke 256th (257th na afo nke ana-kpo leap year) na afo. Anyi nwere agugu ubochi 109 du mgbe afo na agwu.