Irma is now an extremely powerful Category 5 hurricane. It is now the second strongest hurricane on record (as far as wind speed goes) in the Atlantic Ocean with winds of 185mph and wind gusts that exceed 200mph! Hurricane Allen is #1 with max winds of 190mph at it's peak (1980).
Irma is also the strongest Atlantic hurricane east of 60W on record.
EDIT: I forgot however, Irma is actually the strongest Atlantic hurricane (winds and pressure) in a decade. (2007; Dean/Felix)