Developer Niantic has announced this on his blog.
After the update, it is possible to reach a maximum of level 50, instead of the current level 40. Those last ten levels can only be achieved by completing special challenges, such as catching a certain number of monsters in one day.
Creatures from the sixth generation of Pokémon games will also be added. These monsters from the Kalos region were found in the 3DS games Pokémon X and Y. A selection will be added first, including the starting Pokémon Chespin, Fennekin and Froakie.
The game will now pay attention to the seasons, so that monsters appear more often during certain times of the year. Some samples are also special types based on the seasons.
The major update will be released on December 2. Then special events will also start to celebrate the innovations.
Pokémon Go was a big hype years ago, but since then the game has been making significant profit. According to market analysts, recent sales were even higher than in 2016, when the game originally appeared.