We are having a cold snap this week. After some nice bee flying weather we expect temperatures in the 30’s and 40’s this week. The bee’s prefer above 50 F to fly, although I’ve seen some bees flying in temperatures as low as 45 F (7 C). The danger for this time of year is that the bees are ramping up for spring with lots of brood and new bees emerging every day. The hive can be overwhelmed with young adult bees, and if there isn’t enough nectar coming in, the hive can parish during a cold or rainy period.
As a result, every beekeeper gets a little nervous this time of year. If the queen has laid too many eggs and there isn’t enough nectar stored, they can be in real trouble. This is why many beekeepers feed sugar patties in the spring. It is too cold for sugar syrup, but a block of sugar or fondant on top of the hive can provide that extra food the hive needs on colder days.
There are couple ways to check your hives. Some use internal sensors or thermal cameras to find the cluster. You can also listening for their buzzing with your ear against the side. A simple method I use on some hives is a screened bottom board.
I took the following picture this past week. The board slides underneath a screen in the bottom of the hive, hence the name screened bottom board, or SBB. As the bees move around, pieces of wax, pollen, and even pests will fall through and collect on the board. I pulled this out on a cold morning to see how the hive was doing. The board does get dirty over time, you can replace these with political signs cut to fit.

As you can see, the bees are clustering above the top right of this board. They appear to be spread across four frames here (the blank areas with little or no debris), and as they chew through wax and move around the hive, the debris shows their location. If you zoom into the photo, you can see bits of pollen in the debris, and there are three small hive beetles visible as well (the large black spots here).
So on the day I took this picture, the hive seems was likely alive and well.
May you prosper and find honey.