Regions

Regions are an organized areas of the Pokémon world known from previous games about Pokémon such as games from core series. In Pokémon GO there are two regions referred, which are Kanto and Johto.

Kanto
The Pokémon known from Kanto region were the base Pokémon released in Pokémon GO. But not all Pokémon of this Generation were released at this time.

There are currently two Pokémon, that are still not available and not officially scheduled to be released:
 * Mewtwo
 * Mew

History

 * November 22, 2016 – Ditto was released in the games, disguised as other Pokémon.
 * July 22, 2017 to July 30, 2017 – Articuno were available from Raid battles.
 * July 31, 2017 to August 6, 2017 – Moltres were available from Raid battles.
 * August 7, 2017 to August 12, 2017 – Zapdos were available from Raid battles.
 * From August 12, 2017 to August 31, 2017 - All three Legendary Birds were available from Raid battles.

Johto
Johto is so far second region from which Pokémon are available in Pokémon GO. The Pokémon from this region were firstly released in December 2016 as Baby Pokémon available to hatch from Pokémon Eggs.

There are currently several Pokémon, that are still not available nor officially scheduled to be released:
 * Smeargle
 * Delibird
 * Ho-Oh
 * Celebi

History

 * December 12, 2016 - Togepi and Pichu along with another Baby Pokémon and Togetic as evolution of Togepi were released as Pokémon available only to hatch from Pokémon Eggs.
 * February 15, 2017 - over 80 Pokémon from this region were available to catch in the wild and hatch from eggs.
 * July 22, 2017 - Lugia was released as the Legendary Raid Boss and is available to catch only after defeating it.
 * From August 31, 2017 to September 30, 2017 - Legendary Beasts are available as the Legendary Raid Bosses and are available to catch only after defeating them. All three of these Pokémon are exclusive to following regions:
 * Raikou can be battled throughout the Americas
 * Entei can be battled throughout Europe and Africa
 * Suicune can be battled throughout the Asia-Pacific region
 * On September 30, all three of Legendary Beasts will move to a different location and will be available until October 31.
 * On October 31, all three of Legendary Beasts will move to a yet another location and will be available until November 31.

Trivia

 * Another term used in Pokémon GO players community to describe Pokémon groups from each region is Generations. Which also is valid but it wasn't officially referred in game nor by its creators.
 * Therefore Kanto is Generation I, Johto is Generation II, Hoenn is Generation III and so on.
 * More about generations you can find here.
 * Common thing for Pokémon, that are not available with main release of each region Pokémon, is that those Pokémon either are legendary and/or mythical or have certain, special moves like Ditto.
 * There are at most sixteen known regions that have appeared in the various Pokémon canons.
 * There has been Pokémon species from Hoenn added to game code since update 0.71.0.