Having checked almost all my hives recently I have noticed that the amount of brood in the brood chambers is decreasing. The brood ball in most of them is getting smaller.
This reflects the slightly shorter days and the cooler (overnight) temperatures.
My advice to beekeepers is to keep one eye on your honey supplies and be sure that the bees have enough for winter.
I have one eye firmly set on the winter now and making sure my hiveware is in good condition and that honey reserves for the bees are in good supply before I close down my hives for winter. Which may be sooner rather than later actually.