In some years oak and beech trees produce a large amount of seeds, and in other years almost none. 2018 has been a prolific year around these parts.
One theory is, if large quantities of seeds are produced at once, some seed will survive consumption by birds and mammals.
Oak and beech both rely on wind-blown pollen to reach female flowers. If all the trees flower en masse, then chances of fertilization are increased. However, if there is a sudden cold snap, then fertilization will be largely unsuccessful.
So, despite a late cold spring, and the “almost-drought” of a summer, these trees seem to have timed their florescence just right.