Pokemon Go's new weather feature is causing some insanely strong Pokemon to appear in the wild.
For the last year and a half, Pokemon Go has had a secret two-part cap as to how strong Pokemon can be when players catch them. Pokemon won't appear at a level higher than the trainer catching them (so a Level 20 Trainer will never find a wild Pokemon at Level 21) and no wild Pokemon will be higher than Level 30.
However, that may have just changed due to the new Dynamic Weather system just implemented by Pokemon Go. Players are now reporting seeing and capturing Level 32 to Level 34 Pokemon in the wild, all of which appeared due to a "weather spawn." Pokemon that spawn due to the weather have a small ring around it, and it appears that these Pokemon can also have a boosted level in the wild.
Raid Bosses that are affected by the weather also get a boosted level when caught. Usually, all Raid Bosses are caught at Level 20, but those affected by the weather can be caught at Level 25 instead.
Pokemon Go did claim that certain Pokemon in the wild would have boosted CP due to the weather, but players assumed that it referred to either Raid Bosses or a general buff that applies to all Pokemon, wild or tame. No one expected for Pokemon Go to actually exceed its Level Cap, thus giving players access to some great Pokemon without needing to spend Stardust and Rare Candies.
Here's which Pokemon are boosted in certain types of weather:
Clear Weather: Fire-Type, Grass-Type, Ground Type
Partly Cloudy Weather: Normal-Type, Rock-Type
Cloudy Weather: Poison-Type, Fairy-Type, Fighting-Type
Snowy Weather: Ice-Type, Poison-Type
Rainy Weather: Electric-Type, Bug-Type, Water-Type
Windy Weather: Flying-Type, Psychic-Type, Dragon-Type
Foggy Weather: Dark-Type, Ghost-Type