There’s a new global Water Festival event that has been announced for Pokémon GO. Starting today at 1 p.m. PDT, players will be more likely to encounter Magikarp, Squirtle, Totodile and their evolutions all around the world. Additionally, when you’re out exploring areas where Water-type Pokémon more commonly appear, you’ll have a greater chance to encounter several of the Water-type Pokémon originally discovered in the Johto region and you might even encounter Lapras. Also, starting later today, you’ll notice a new avatar wardrobe item – the Magikarp Hat. The Pokémon GO Water Festival is a limited-time celebration and will come to an end on March 29, 2017, at 1 p.m. PDT.
Source: Pokémon GO blog