The colony's aim throughout the season is to store enough honey to keep it going through Winter. It means they need to have about 40 lbs of honey stored, which they can collect from Spring until September when Ivy, the last nectar source, is in flower. Getting our bees ready for Winter means checking they have enough stores and putting a mouse guard over the entrance to stop the little blighters coming in to make the most of a warm hive in the cold months.
The bees don't hibernate, instead they huddle together like penguins do and, like penguins, the bees take turns to be on the outside of the huddle so they all share the pain of the colder spot. The temperature inside the hive is kept constant, whatever the weather outside; they do this by dislocating their wing muscles and vibrating to generate body heat. The Queen stays in the middle of the cluster and slowly they move as one around the hive from honey store to honey store. The ideal is for a tight cluster that has honey within very easy reach: it means the bees keep quiet and don't use much energy so the chances of getting though Winter without starving are higher. It's warm winters that encourage the cluster to break, the bees to venture outside, and the Queen to lay eggs that worries beekeepers as the colony will eat more and can run out of stores and starve.
The best sight in the world is seeing your bees emerge from the hive in early spring and know that so far, so good!