 Later on August 21, Iris turned northwestward as the ridge weakened and brushed the northeastern tip of Luzon.On August 22, Iris attained its peak intensity as a Category 2 equivalent typhoon on the Saffir–Simpson Hurricane Scale with winds of 165 km/h (105 mph).Later that day, United States Air Force reconnaissance plane flew into the storm and recorded a barometric pressure of 966 mbar (hPa; 28.53 inHg), the lowest in relation to the storm.