The mighty Lunatone and Solrock have officially swapped locations in Pokémon GO. This move was done in honor of the summer solstice, which happens to be the longest day of the year. Lunatone and Solrock never appear in the same region at the same time. The official announcement from Pokémon GO developer Niantic is as follows.
In honor of the summer solstice, the Rock- and Psychic-type Pokémon Solrock and Lunatone have started to appear in different regions! Celebrate the longest day of the year by adding one to your Pokédex today!