Niantic has announced that a Hoenn themed event will take place from January 15th, 2019 until January 29th, 2019. Pokémon originally discovered in the Hoenn region will be appearing more frequently in the wild.

Celebrate the Hoenn region during this new event!

Trainer, We’re kicking off the new year with a brand-new celebration! Starting on January 15 at 1 p.m. PST and going until January 29 at 1 p.m. PST, Pokémon originally discovered in the Hoenn region will be appearing more frequently in the wild. Plus, if you evolve Shroomish into Breloom during the event, it will know the exclusive move Grass Knot! See more details below:

Event Date + Time
Jan. 15, 2019, at 1:00 p.m. PST (GMT −8) to Jan. 29, 2019, at 1:00 p.m. PST (GMT −8)

Features

• Pokémon originally discovered in the Hoenn region will appear more frequently in the wild.
• Field Research will highlight Pokémon originally discovered in the Hoenn region.
• Raid Battles will include Pokémon originally discovered in the Hoenn region, such as the Legendary Pokémon Kyogre and Groudon.
• Pokémon originally discovered in the Hoenn region will have an increased chance of hatching from 7 km Eggs.
• If you evolve Shroomish into Breloom, it will know the exclusive move Grass Knot!
• You’ll have a chance of encountering Shiny Zigzagoon and Shiny Taillow!
• New avatar items inspired by Team Magma and Team Aqua—the original villains of the Hoenn region in Pokémon Ruby and Pokémon Sapphire—will be available in the Style Shop.

So celebrate the spirit of the Hoenn region together! Stay safe, and happy exploring!

Source: https://pokemongolive.com/en/post/hoenn-jan2019/