  The propagation of ultra-high energy cosmic rays in extragalactic magnetic
fields can be diffusive, depending on the strength and properties of the
fields. In some cases the propagation time of the particles can be comparable
to the age of the universe, causing a suppression in the flux measured on
Earth. In this work we use magnetic field distributions from cosmological
simulations to assess the existence of a magnetic horizon at energies around
10$^{18}$ eV.
