Max Battles are co-op fights at Power Spots, which are their own map points rather than Gyms or PokéStops. The reward is a Dynamax Pokémon. It's the newest system in the game.

When they happen

Both land on the calendar, and the Max page lists what has been announced. Max Monday shows as an expected row until Scopely names that week's species.

Dynamax this season

The Twilight Trails season post names these:

Questions people ask

What are Max Battles in Pokémon GO?

Co-op fights held at Power Spots, and the reward is a Dynamax Pokémon. They're the newest system in the game.

What is a Power Spot in Pokémon GO?

Its own kind of map point. A Power Spot is not a Gym and not a PokéStop, so a Max Battle happens somewhere a raid never does.

Are Max Battles the same as raids?

No. Different map points, a different fight, and a Dynamax Pokémon rather than a raid boss encounter. Raids stay on Gyms.

When is Max Monday?

Mondays, 6 AM to 9 PM local time, with that week's featured Dynamax Pokémon at Power Spots all day. It runs weekly, so the calendar carries it as an expected row until Scopely names that week's species.

What is Max Battle Day?

The Max system's version of a Raid Day: announced, a few times a season, rather than weekly. Announced ones land on the Max Battles page.

Which Pokémon are Dynamax right now?

The Twilight Trails season post names Sizzlipede, Mesprit, Rhyhorn, Sneasel, Azelf, Uxie.