Season of Celebration

Season of Celebration was the first Season in Pokémon GO. It was announced on the update GO Beyond. This Season celebrated the real world winter in the north hemisphere and summer in the south hemisphere.

During this Season, Trainers were able to participate in a series of in-game events featuring Pokémon first discovered in different regions (Kanto, Johto, Hoenn, Sinnoh, Unova, or Kalos). At the end of the Season of Celebration, a brand-new global event experience was introduced: Pokémon GO Tour: Kanto

Featured Pokémon
Two Deerling forms were released at the start of the Season:

Winter-themed Pokémon had increased spawn rates in the wild and from Incense or Lure Modules in the northern hemisphere:

Summer-themed Pokémon had increased spawn rates in the wild and from Incense or Lure Modules in the southern hemisphere:

List of Season of Celebration Events
During this Season, there were 21 events, 1 of them being regional.