Good job ! Supposedly the Tioga Pass area got a pretty much normal snowpack this year, so I'm not surprised North Peak's couloirs are still snow.
For good ice to form, we need melt / freeze action. Emphasis on "freeze" -- during the height of summer the days are long, the nights are not so cold and the sun's angle is high.
Later on as August starts to wane, the nights start to get longer & chillier and the sun's angle lowers. These are subtle but significant effects.
In mid-August 2005 I went up the right couloir of North Peak .. we encountered more ice than we expected, but it wasn't very good... as the sun rose it hit the snow up above and water ran down the couloir .. kinda unsettling when you're using ice screws with water running down them
IMO Take your time, climb some nice warm rock routes instead, and leave the ice for later, when it actually starts to get cold again