The company looked at iOS-based online ad impressions from May 22 through May 28, 2014.
Nearly 90% of U.S. and Canadian iPhone Web traffic is generated by users running some version of iOS 7. This share represents an increase of 5.4 percentage points since our February study on the subject.
Looking at iPad usage figures, while not quite matching the adoption rate on iPhones, iOS 7 users still constitute the vast majority of total U.S. and Canadian iPad Web traffic at just under 85%. This is a share increase of 6.3 percentage points since the February report.
Last year, iOS 6 adoption was at 92.7% for the iPhone and 82.9% for iPad prior to WWDC.
Apple is expected to unveil iOS 8 next week. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.