Niantic has announced new changes to the Season of Mischief which will starts on Wednesday, September 1st, 2021, at 10:00 a.m. local time.

Global Bonus Changes:

Trainers, As a result of our recent task force discussions, we will be replacing the two current sets of region-based bonuses with one set of global bonuses at the start of the Season of Mischief.

Because these changes will begin at the start of the Season, we wanted to make sure we shared this information prior to our full task force update on Wednesday, September 1, 2021.

During the Season of Mischief, Trainers in the United States and New Zealand will see the following bonus updates.

New bonuses:

• 3× bonus XP for spinning PokéStops for the first time
• 2× Lure duration
• Increased Incense effectiveness
• Additional Incense effectiveness while walking
• Boosted damage for Trainers battling remotely in raids
• Guaranteed Gifts from PokéStop spins
• Buddy Pokémon will bring you Gifts more often

Bonuses no longer in effect:

• 10× XP for spinning PokéStops for the first time
• Up to two free Raid passes per day by spinning Gym Photo Discs

During the Season of Mischief, Trainers outside the United States and New Zealand will see the following bonus updates:

New:

• Increased Incense effectiveness while walking
• 3× bonus XP for spinning PokéStops for the first time
• 2× Lure duration
• Increased Incense effectiveness
• Boosted damage for Trainers battling remotely in raids
• Guaranteed Gifts from PokéStop spins
• Buddy Pokémon will bring you Gifts more often

Source: https://twitter.com/PokemonGoApp/status/1432797410376380420