From a facebook friend:" I had installed a thermometer with a removable probe in my hives. I checked the temps yesterday when it was zero degrees outside -- it was 87.6 degrees where the probe was inside the hive. The cluster must have been nearby. It just amazes me how warm their clusters are!"
Bees start winter in the bottom box (two box hive) or the middle box (three box hive). In most hives this time of year the cluster of bees have moved up in the hive. The cluster of bees should now be in the top box. That is why bees store honey above them. They move up in the winter. The warmest part of the hive is the top box because heat rises making it easier to keep the brood warm. The queen will start laying in around two to three weeks and the cluster of bees will be eating more honey to produce heat to keep the brood warm. So by mid Feb a hive food check is a must.