10x12 "The One with Phoebe's Wedding"

Phoebe's wedding to Mike is nearly upon the gang, and wedding planner Monica is going overboard much to everyone's irritation. Eventually it gets too much for Phoebe who fires her intending to do the job herself. Meanwhile Phoebe has also asked Joey to give her away, causing him to give Mike more than a few warnings about Phoebe's welfare. Ross and Chandler also find they're not part of the wedding party but compete when one of Mike's groomsmen drops out and he offers to let one of them fill the position. A freak blizzard hits New York and it becomes obvious the wedding will have to be postponed, but Phoebe and Mike decide to get married outside with a still-ordained Joey acting as minister and Phoebe rehires Monica knowing she can pull it all off in time. Mike tells Ross and Chandler that he's decided to allow his family dog to fill in the vacant groomsman position but still needs one of them to walk the dog down the aisle and Chandler's fear of dogs allows Ross to fill the role only while Chandler fills in for Joey giving Phoebe away. In the end, everything works out and Phoebe has the wedding of her dreams in the snow-filled street outside Central Perk.
Note: Originally aired as a 42-minute episode.