Might be useful to a Zurich operator, tho.
To be honest, as Zurich-based (airline tho...) crew, it's hardly ever below CAT I for prolonged periods of time. Morning fog may mess it up for an hour or three, same in the evening.
Sure, they built the airport in the foggiest piece of real estate they could find, but to be honest even with my airline schedule I rarely do more than two or three actual CAT IIIs a year.