oak tree losing leaves July

Hello - is there anyone with knowledge of tree health - in particular Oak? My suburban garden is dominated by a wonderful Oak tree abt 55 yrs old and 50ft high. It has struggled this year for the 1st time in its life - the first leaves soon curled and looked almost dirty rather than fresh. I assumed it was the cold, but maybe it was the first stage of mildew - a second try of leaves which looked normal have now become covered in white/grey mildew. Dried leaves are now (end July) falling as though it is autumn. (The bark looks fine and no sign of insect infestation).

Will the tree die?

No, mildew won't kill a tree of that age. You will probably get a third flush if it loses all of these; if not, you might have to wait until next spring, when it'll hopefully be free of mildew.

Thanks Alina W - that's a nice emphatic 'no', and I feel quite relieved.

I know of no other oaks anywhere near so have thought our tree was safe from 'oaky' diseases being passed to it via air or animals - but perhaps this mildew is less species specific.