I was going to call this post 'Lifting the Lid on Winter Inspection' but was concerned someone may open a hive in winter! Unless you live in a warm climate then you could be making a big mistake. The cluster in a hive needs to maintain warmth of 32 to 35 degrees C. That is some achievement in a cool climate. As you move away from the cluster the temperature can drop quite dramatically. Near the end of winter, the bees have been nurturing brood and are working hard to maintain these high temperatures. Below 15 degrees C the brood will die. We know there are three things that help bees survive winter.
Firstly, having a box of honey above the cluster helps to both insulate and feed the bees, and they need feed to stay warm. Secondly, the hive set-up assists the bees. If there is good insulation at the top of the hive this will help keep some warmth just above the cluster.. The old timers in our cool climate add carpet squares between the hive mat and the lid. Some of us use a quilt box as used on warre hives. Filled with pine shavings it provides good insulation as well as moisture control. The third thing that helps bees during winter is their ability to seal up every crevice and crack to reduce heat escape and cold drafts.
When a hive is opened, all this seal is disturbed and takes many days to repair. In winter it takes even longer. When we open a hive even on a warm winter day we risk a serious loss of heat and the possibility of an unsealed hive for many days, so if the weather gets cold as it often does, we may be harming the bees. I know it is hard waiting for the start of the season but keep your nerve and wait until we have some consistently warm weather.