Hi , was wondering if anyone had ever come across this scenario? was fishing my local river Blyth (N/LAND) yesterday there was a steady hatch of mayflies , but not one rising fish ! tried everything dries ,spinners , nymphs and not one sign of a fish !! the swallows and martins were having a field day

the weather was overcast with heavy showers ,i was wondering if the showers were putting the fish of ? i know they are there as i have had success all season on the same beats,
Thoughts please
cheers Bob