Raikou is now avaiable as limited time raid boss for the next 3 months. For the first month, from August 31 to September 30, he will be available in the Americas. He will then switch regions on September 30 and October 31, so stay tuned to find out where he will appear next.
Tips and strategies
Recommended attack types
As a pure Electric-type Pokemon, meaning his only weakness are Ground-type attacks, so use this type of attacks to defeat Raikou before time runs out. On the other hand, do not use Electric, Steel or Flying-type attacks against Raikou as he is resistant to these types of attacks.
All of his attacks are Electric-type, so the only types that can resist him are Ground, Dragon, Grass and other Electric-types. The only Viable Dragon-type Pokemon as of now is Dragonite, which is also part Flying-type, making Electric attacks do neutral damage instead of resisting them. Using Grass or other Electric-type pokemon will most likely do little damage to him. Leaving you with only the option of Using Ground-type Pokemon
Raikou's pure Electric typing forces you to use Ground-type Pokemon. If not, you will either do little damage or take large amounts of damage because of Raikou's extremely high attack stat.