Niantic has announced that the Pokémon GO Battle League Season 3 begins Monday, July 27, 2020.

GO Battle League Season 3 begins Monday, July 27, 2020, at 1:00 p.m. PDT (GMT −7)

Trainers, Season 2 of the GO Battle League is nearing its end, and we’re excited to share all that’s happened within the past several weeks!

GO Battle League Season 2 Recap
There were a lot of changes that happened in Season 2! Trainers who reached rank 10 earned a fun new avatar pose. We tested out the Premier Cup format, and it was so well received that we decided to bring it back for Season 3.

We’re also excited to share that Trainers have completed one billion battles in the GO Battle League! We are thrilled to bring Trainers even more opportunities to battle during Season 3.

Season 2 rewards, Season 3 timeline, and what to expect
Once Season 3 begins on Monday, July 27, 2020, at 1:00 p.m. PDT (GMT −7), your end-of-season rewards for Season 2 will be available on the Battle screen! You can expect similar end-of-season rewards for Season 2, except that you’ll receive an Elite Fast TM instead of Elite Charged TM if you reached rank 7 or higher! Season 3 will follow the same league rotation as Season 2, as noted in the schedule below, with a notable addition: the Premier Cup is now coming to Ultra League, too!

• The Great League will run from Monday, July 27, 2020, at 1:00 p.m. to Monday, August 10, 2020, at 1:00 p.m. PDT (GMT −7).
• The Ultra League and its Premier Cup will run from Monday, August 10, 2020, at 1:00 p.m. to Monday, August 24, 2020, at 1:00 p.m. PDT (GMT −7). This Premier Cup will have a 2500 CP limit.
• The Master League and its Premier Cup will run from Monday, August 24, 2020, at 1:00 p.m. to Monday, September 7, 2020, at 1:00 p.m. PDT (GMT −7). This Premier Cup will have no CP limit.
• All three leagues and the Premier Cup (no CP limit) will be available from Monday, September 7, 2020, at 1:00 p.m. to Monday, September 14, 2020, at 1:00 p.m. PDT (GMT −7).
• Season 4 will begin Monday, September 14, 2020, at 1:00 p.m. PDT (GMT −7).

These dates are tentative, and we’ll be sure to update you if anything changes.

Expect the following to stay the same in Season 3:

• There will not be a walking requirement in order to battle in the GO Battle League.
• The Friendship level requirement for battling remotely will remain at Good Friends throughout Season 3. Remember that you can scan another Trainer’s QR code to battle them, no matter where they are.
• The avatar items inspired by Pikachu Libre will continue to be rank 7 rewards.
• The battles, wins, and ratings required to reach ranks will remain the same.

What’s new in Season 3?
There’ll be a few changes coming to the GO Battle League and Trainer Battles for Season 3.

• More cups will be added! In addition to the Ultra League Premier Cup, we’re introducing the Flying Cup, where only Flying-type Pokémon will be allowed! The Flying Cup will be available during an upcoming event—more details to come!
• Based on Trainer feedback, we’ve decided to remove the Battle Until You Win feature for Season 3.
• Your guaranteed reward encounters will be a bit different for Season 3. At each listed rank, you'll encounter these Pokémon:
• Pidgeot starting at rank 1
• Galarian Zigzagoon starting at rank 4
• Galarian Farfetch’d starting at rank 7
• Rufflet starting at rank 8
• Scraggy starting at rank 9
• Pikachu Libre starting at rank 10
• If you reach rank 10, you’ll earn a brand-new avatar pose and avatar item!
• For the premium rewards track, you’ll now earn Rare Candies after your fourth win. The number of Rare Candies rewarded will be reduced from eight to six.
• Trainers who finish Season 3 at rank 7 or higher will receive an Elite Charged TM rather than an Elite Fast TM. Besides that change, end-of-season rewards will stay the same as in Season 2.

Additionally, we have two GO Battle League–themed events lined up for Season 3! Stay on the lookout for updates regarding these events on the Pokémon GO blog and social media.

The following existing attacks have been updated for Trainer Battles.

• Drill Peck: This Flying-type Charged Attack now deals more damage.
• Brave Bird: This Flying-type Charged Attack now deals more damage. It also severely lowers the user’s Attack.
• Infestation: This Bug-type Fast Attack now generates energy more quickly.
• Hex: This Ghost-type Fast Attack now generates energy more quickly.
• Powder Snow: This Ice-type Fast Attack now deals more damage.
• Blizzard: This Ice-type Charged Attack now deals more damage.
• Flash Cannon: This Steel-type Charged Attack now requires more energy.
• Focus Blast: This Fighting-type Charged Attack now deals less damage.
• Moonblast: This Fairy-Type Charged Attack now has a decreased chance of lowering your opponent’s Attack.

The following existing attacks have been updated for Gym battles and raids.

• Drill Peck: This Flying-type Charged Attack now deals more damage.
• Brave Bird: This Flying-type Charged Attack now deals more damage.
• Hex: This Ghost-type Fast Attack now generates energy more quickly.

Along with these updates to existing attacks, the following Pokémon can learn an attack they couldn’t before.

• Braviary and Close Combat: Braviary can use this attack to make opposing Rock- and Steel-type Pokémon more dependent on Protect Shields.
• Abomasnow and Ice-type Weather Ball: This Ice-type Charged Attack is fitting for a Pokémon that appears when it’s snowy.
• Pelipper and Water-type Weather Ball: This Water-type Charged Attack is fitting for a Pokémon that appears when it’s rainy.
• Empoleon and Drill Peck: Empoleon can use this attack to make Fighting-type Pokémon more dependent on Protect Shields.

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/en/post/gobattleleague-season3/