What temperature is too cold for honeybees?

Though honeybees are truly amazing animals, they are also cold-blooded insects and as such, their bodies can’t handle extremely cold temperatures. In the winter months, honeybees are only able to survive within their cluster (not hibernate) until spring because of their strength in numbers. The entire colony of bees works together to vibrate their muscles and generate heat, keeping the cluster and queen safe at a temperature between 90-95 degrees (F).  

As soon as the temperature drops below 40 degrees F, the temperature becomes too cold and is unsafe for individual honeybees to survive. Instead, winter bees will tightly form together within their cluster. Though they may break the cluster briefly on warmer days to take cleansing flights, you should be very careful not to open the hive unless absolutely necessary on days that are 50 degrees F or colder. Instead, check your hive from the outside or use in-hive monitors instead to avoid disturbing the colony and cluster. (See the “Read More” section below for an article about the benefits of using in-hive monitors in your beehives.) 

When a colony is too small to generate enough heat even with a cluster of bees, or there aren’t enough food reserves to sustain them through long periods of extreme cold, honeybees can face real danger. Ahead of winter, making sure your colony has enough food stores and that their hive is well insulated can help give them a much better chance at survival.  

Cold temperatures do pose a risk to colony survival, but a much bigger threat comes from the potential of moisture and condensation* build-up inside the hive. Condensation can build up from bees generating heat inside the hive while the outside is SO cold. This can cause bees and brood to become cold and wet, unable to maintain warmth or stay in their cluster. Ensuring the hive is properly ventilated and insulated before winter starts can help to mitigate this risk. (*Colony Members, see the “Read More” section below for an in-depth Academy lesson about managing temperature and moisture in your beehives) 

Read More

Inside and Out of the Beehive

When Advanced Monitoring Meets Beekeeping

Beehive Insulation for the Winter

How Honeybees Manage Temperature and Moisture *

 * Colony Member-Only Content