In this blogpost I will be debunking some flim flam that you might’ve picked up in bee school. This idea that it has to be 55 degrees (fahrenheit) or above to open up your hives is mostly false. Here in Charlotte, NC I lived by this code for many years of beekeeping and it might’ve been the demise of my hives rather than helping them.
The idea behind this is that this magic number 55 is the temperature at which, when exposed to, baby bees aka brood will die. This is known as chilled brood and it can be observed by the white, pupated bodies of baby bees being found on the landing board of the hive after the event. What’s amazing is that the bees, when forming a cluster in the hive, can keep the temperature regulated to something above 55 degrees. However if you open the hive up in temperatures at or below 55 degrees you are potentially breaking the cluster and thus disrupting the temperatures they’ve been trying to keep the hive at.
Note here I AM NOT SUGGESTING YOU BREAK THE CLUSTER within your hive when doing an inspection! This means that you shouldn’t pull frames apart. However I’ve found it inconsequential to pull the boxes apart so long as it’s not for too long. Outer frames, or the ones that are outside of the cluster, are okay too. At this point of the year, you really shouldn’t need to do a very thorough inspection anyways. That time has come and gone. When I’m opening these hives I’m mainly just checking to see how they’re doing (activity on top of the frames) and more importantly needing to add food in the form of sugar bricks.
There are times however that call for more involved inspections where I do need to pull frames apart. This can still be done in winter with temperatures below that magic number. I just wouldn’t recommend doing it for very long as that can chill the brood. Also note that all of my hives are in full sun throughout the day. I placed them there for this very reason! Not only do they stay warmer in the winter, but the exposure to the Sun allows for these inspections.
Note also where our hives are geographically. Charlotte, NC is not only in the southeastern region of the US, where we rarely get snow (currently 730 days without snow as I type this), it also happens be one of the lower areas of the state of North Carolina. Being so, Charlotte, NC generally has fairly mild winters with high temperatures usually ranging around 55 degrees. This means that all of what I'm prescribing in this blogpost may not be relevant to your region. If you've bundled up your hives for the winter like they do in the Northeast, best to keep them that way until the winter is over.
All this to say, if you feel you do need to crack open your hives in the dead of winter and it's not super duper cold, go for it! Making sure your bees have plenty of food is way more important than keeping them sealed shut. Feral hives survive all winter in the tops of tree branches! That means they’re completely in the open getting blown around by the wind all day! They can take a little cold every now and then so long as it’s not super cold (below 40 degrees) and it’s not for very long.