Every year around this time, typhoons hit that island.
Literal
Every-year this around-time, typhoon [subject-が] that island [object-を] attacks.
今頃 ('around now, at this time of year') is a temporal noun specifying an approximate time. 襲う ('to attack, to hit') is vivid verb for natural disasters — typhoons, floods, earthquakes — using the metaphor of hostile assault.