Events

Events are either in-game or both in-game and real-world celebrations for special occasions. Events can last one day or several weeks and grant trainers a chance to complete their Pokédex by increasing the chance of acquiring rare or special Pokémon.

During them, there are various temporal changes to the game that can be applied (bonuses and perks for trainers) such as:
 * Specific Pokémon spawn increased.
 * Specific Pokémon in temporary Eggs, Raid Battles and Research tasks.
 * Specific Pokémon wearing event-themed hats.
 * Extended duration of Star Piece, Lucky Egg, Lure Modules and Incense.
 * Increase of Incubator efficiency.
 * Reduced buddy distance and trading cost.
 * Multiplied Stardust, Candy and XP for several actions such as hatch, catch, transfer, evolving and battling.
 * Release of specific Pokémon species, forms, shiny and shadow variants.
 * Release of Special or Timed Research tasks.
 * Special shop offer.
 * Specific attacks.

There are three major kinds of events:
 * Unique events: events that happened only once.
 * Seasonal events: events that happened more than once. Normally, these events are related to holidays and they do not tend to happen more than once a year.
 * Recurring events: events that happened more than once but are neither seasonal (?) nor related to special occasions.

Moreover, some events are worldwide available, while others can happen in a specific region. For instance, some events happened only on Europe, while others happened only on Japan.

Sometimes events can be also ticketed for an access to all its features and bonuses.

Unique and seasonal events
There were 5 unique/seasonal events during 2016, 1 of them was regional event. There were 23 events during 2017, 11 of them were regional events. There were 32 events during 2018, 5 of them were regional events. There were 41 events during 2019, 8 of them were regional events. There were 52 events during 2020, 1 of them was a regional event.

Recurring events
There are plenty of events that happen to reoccur either regularly or not. They differ from seasonal events as they may occur more than once in the same year.

Nest migrations
Nest Migrations are the technical changes to the game rather than ongoing events in which Pokémon Nests changes species which spawns in the specific locations. It occurs regularly since Jul, 2016.

Pokémon GO Safari Zone
Pokémon GO Safari Zone is a recurrent regional event, that happens in different locations around the globe. The events give Trainers the ability to catch region-exclusive Pokémon that do not usually appear in these regions. It occurs irregularly since Aug, 2017.

Community Day
Community Day is the first regular event that mostly lasts few-hours on one, particular day of each month and during it players can catch a Pokémon with an exclusive move that cannot be obtain normally in game play. During this event players have a significantly higher chance of obtaining shiny variant of featured Pokémon. It occurs regularly since Jan, 2018.

Special Raid Challenge
Special Raid Challenge is a recurrent event that is hosted during a three-hour window and features a Pokémon as Raid Boss. This Pokémon may know one or more limited or legacy attacks and may also have a chance to be shiny. All Trainers receive up to five Raid Passes from Gyms at no cost. It occurs irregularly since Jul, 2018.

Pokémon GO Special Weekend
Pokémon GO Special Weekend was an recurring regional event. It occurs irregularly since Jul, 2018.

Special Raid Event
Special Raid Event (also dubbed Week or Weekend) is a recurrent event that is hosted during a short period of time and features a returning Legendary Raid Boss which may have a chance to be shiny. It occurs irregularly since Dec, 2018.

Limited Research
Limited Research is a recurrent event that is hosted for a few hours and features exclusive Research tasks that may reward a Trainer with a shiny Pokémon. It occurs irregularly since Jan, 2019.

Legendary Raid Hour
Legendary Raid Hour is an occasional event that turns every available Gym to a specific Raid Boss during one hour. It usually occurs on Wednesday from 6 p.m. to 7 p.m. in local time zone. It occurs regularly since Mar, 2019.

Pokémon Spotlight Hour
Pokémon Spotlight Hour is weekly event that took place for the first time in February, 2020. It occurs on Tuesdays and lasts one hour. During the event there is increased number of Pokémon to appear in wild. When particular Pokémon species is featured in this event and it has its Shiny form released prior to the specific Spotlight Hour, there is a higher probability of catching it due to the increased spawns. It occurs regularly since Feb, 2020.

Mystery Bonus Hour
Mystery Bonus Hour was a regularly recurring event that solely featured bonuses for Candy, Stardust, or XP. It occurred on Thursday evenings in local time zones before being discontinued as a separate event and merged with Pokémon Spotlight Hour. It is discontinued and occurred from Feb, 2020 to Apr , 2020.

Event Pokémon
Event Pokémon are Pokémon that have unique accessories or clothing such at hats, glasses or scarves and can only be obtained during an special event. They cannot be mass-transferred, similar to Legendary, Mythical, or Shiny Pokémon. They usually do not appear in the Pokédex, because they are not handled as forms.