And finally, it also need the airport/runway to be equipped. Most of the major airports have suitably equipped runways, and of course wind is not normally a factor, being that its normally mist or fog that causes the conditions to be Cat 3, for which there needs to be not much wind.
Not all destinations are Cat 3 certified.
So you need - aircraft fully serviceable and operating to Cat 3, crew fully certified and current, airport and more specifically runway, equipped.
By the way, just to add, Cat 3b is lower than 50 feet (often zero feet) and 75m viz (so's you can taxi the thing once you are on the ground).