Niantic has announced the details of the events that will take place in Pokémon GO throughout September 2021.

Coming in September: Get ready for the Season of Mischief and more!

Trainers, The Season of Mischief begins in just a few days! There’ll also be plenty more to look forward to coming in the month of September.

September Research Breakthrough encounters
From Wednesday, September 1, 2021, at 1:00 p.m. to Friday, October 1, 2021, at 1:00 p.m. PDT (GMT −7), you’ll encounter Ditto in Research Breakthrough encounters. For the first time ever outside of Special Research, you might encounter a Shiny Ditto, if you’re lucky! You might also find a Shiny Ditto in the wild during and after this period.

Weekly 1 PokéCoin bundles
Every Monday in September, a one-time-purchase bundle containing a Remote Raid Pass and other items will be available in the shop for 1 PokéCoin.

Featured Pokémon in raids
The following Pokémon will be appearing in five-star raids throughout September.

• Lugia with the attack Aeroblast will be appearing in five-star raids from Wednesday, September 1, 2021, at 10:00 a.m. to Tuesday, September 14, 2021, at 10:00 a.m. local time.
• Depending on your region, Uxie (Asia-Pacific), Mesprit (Europe, the Middle East, Africa, and India), or Azelf (the Americas and Greenland) will be appearing in five-star raids from Tuesday, September 14, 2021, at 10:00 a.m. to Friday, October 1, 2021, at 10:00 a.m. local time. For the first time ever in Pokémon GO, you might find a Shiny one, if you’re lucky!

In addition, the following Mega-Evolved Pokémon will be appearing in Mega Raids.

• Mega Slowbro will be appearing in Mega Raids from Wednesday, September 1, 2021, at 10:00 a.m. to Tuesday, September 14, 2021, at 10:00 a.m. local time.
• Mega Houndoom will be appearing in Mega Raids from Tuesday, September 14, 2021, at 10:00 a.m. to Friday, October 1, 2021, at 10:00 a.m. local time.

Every Wednesday in September, a Raid Hour event will occur from 6:00 p.m. to 7:00 p.m. local time. The following Pokémon will be featured.

• Wednesday, September 1, 2021: Lugia with the attack Aeroblast
• Wednesday, September 8, 2021: Lugia with the attack Aeroblast
• Wednesday, September 15, 2021: Uxie (Asia-Pacific), Mesprit (Europe, the Middle East, Africa, and India), or Azelf (the Americas and Greenland)
• Wednesday, September 22, 2021: Uxie (Asia-Pacific), Mesprit (Europe, the Middle East, Africa, and India), or Azelf (the Americas and Greenland)
• Wednesday, September 29, 2021: Uxie (Asia-Pacific), Mesprit (Europe, the Middle East, Africa, and India), or Azelf (the Americas and Greenland)

Pokémon Spotlight Hours
In the month of September, Pokémon Spotlight Hour will take place every Tuesday from 6:00 p.m. to 7:00 p.m. local time, and each will spotlight a different Pokémon and a special bonus!

• Tuesday, September 7, 2021: Spoink will be in the spotlight, and you’ll earn twice the Stardust for catching Pokémon.
• Tuesday, September 14, 2021: Baltoy will be in the spotlight, and you’ll earn twice the XP for catching Pokémon.
• Tuesday, September 21, 2021: Skitty will be in the spotlight, and you’ll earn twice the Candy for catching Pokémon.
• Tuesday, September 28, 2021: Alolan Meowth will be in the spotlight, and you’ll earn twice the Candy for transferring Pokémon.

September Community Day
Join us on Sunday, September 19, 2021, from 11:00 a.m. to 5:00 p.m. local time for a Community Day event featuring Oshawott, the Sea Otter Pokémon! Oshawott will be appearing more frequently in the wild and near PokéStops with Rainy Lure Modules. Evolve Dewott (Oshawott’s Evolution) during the event or up to two hours afterward to get a Samurott that knows the Charged Attack Hydro Cannon. Samurott will also be able to learn its signature attack, Razor Shell, via Charged TM during and after this event. For more details, check out the September Community Day blog.

Upcoming events
Stay tuned for details about these upcoming events.

• Season of Mischief: As the Season of Discovery ends, the story of Pokémon GO continues with mischief! Hoopa, the Mischief Pokémon, will be able to be caught for the first time ever in Pokémon GO! To celebrate Hoopa’s arrival, a one-day event will take place on Sunday, September 5, 2021, featuring various strange phenomena happening all around the world—maybe these events have something to do with Hoopa? There will also be a season-long Special Research story available, with parts of the story only being unlocked during certain events throughout the season. To learn more about what’s in store for this upcoming Season, check out the Season of Mischief blog!
• Psychic Spectacular: This event featuring Psychic-type Pokémon returns from Wednesday, September 8, 2021, at 10:00 a.m. to Monday, September 13, 2021, at 8:00 p.m. local time! Some familiar faces will be returning, and another Pokémon will be making its Pokémon GO debut. Which will it be? Here’s a hint: be careful of revolving too much of your life around one thing—you might find that it could overturn at a moment’s notice!
• Fashion Week: Stylishly dressed Pokémon will be making their debuts, along with a fluffy and fashionable friend! Strut your stuff with these fashionable Pokémon, new avatar items, and more during Fashion Week, taking place from Tuesday, September 21, 2021, at 10:00 a.m. to Tuesday, September 28, 2021, at 8:00 p.m. local time.
• Team GO Rocket’s Boss seems to be missing...: Where has Giovanni gone? We hope he’s not planning something in the shadows! Be sure to keep an eye out for updates throughout the season. Super Rocket Radars won’t be able to track down Giovanni during this time, so no need to keep them equipped.

New Evolution preview feature coming soon!
Battlers, rejoice—soon, you’ll be able to preview your Pokémon’s post-Evolution CP before you evolve it! This new Evolution preview screen will display the following.

• The current Pokémon and its CP
• The Pokémon’s Evolution and its new CP
• The leagues the Evolved Pokémon would qualify for

This feature will go live sometime in September. We hope this will help you better determine which Pokémon to power up and evolve.

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

Source: https://pokemongolive.com/post/sept-2021-events/?hl=en