Mike Rapoport wrote:

Most Cat II and III approaches are at major airports. One of the
requirements is that the runway must have centerline lighting which is
generally only found at the largest airports.

Could the presence of a CAT II or III approach also be a function of a
greater occurrence of low visibility? My home airport, Syracuse (KSYR),
has a CAT II ILS, yet it is only a class C airport. During the winter we
experience heavy lake effect snow bands off Lake Ontario and I had
suspected that this was the reason for a CAT II ILS rather than its size.

--
Peter