American peak with worse weather (7)
I believe the answer is:
rainier
This clue is a double definition.
'american peak' is the first definition.
(Mount Rainier)
'with worse weather' is the second definition.
(rain is bad weather)
(Other definitions for rainier that I've seen before include "more cats and dogs?" , "More wet - Monaco's late prince" , "more drops?" , "Mountain" , "Former prince of Monaco" .)