Oak winter leaf drop or something else?

[Scrogdor]

This was a nursery stock Oregon white oak I picked up in fall. It’s a deciduous oak, one of the only trees I have that still has its leaves. However the leaves are browning/ yellowing. I haven’t done anything to it besides slip pot it into an airpot that was the next size up. with the same highly organic “bonsai” soil the nursery used. It’s been very rainy past month or so.

Not familiar with what deciduous oak leaves look like when they change.

 

[Potawatomi13]

"Normally" Quercus garryanna leaves here turn like yours yellow and/or brown. Not very colorful. If Summer very dry, Fall normally frosty more color "may" result. Your warmer zone has kept leaves longer on tree. H2O well but no WETness. If wishing to bend this trunk use heavier wire, do before next Spring growth. Once hardened off bend small branches before getting thicker. Branches bent as soon as leaves mature in Summer/early Fall time. Personal trees with good care have partial 2nd, maybe 3rd growth flush so can wire couple times a year in spots.

 

[Bonsai Nut]

Looks normal to me... particularly if you picked it up this fall in another climate and moved it to Oakland. Depending on the temps you are getting, it may barely drop leaves... almost looking like it would keep them through the winter. Q. garryana occurs naturally on mountain slopes almost all the way south to LA.