Moving the BroodMinder sensor

Graph Interpretation
This hive is built from three stacked 5-frame deep boxes—what I call “the tower.” By late July, my BroodMinder temperature graph became nearly impossible to interpret. Frustration set in: back in May, this same 2025 swarm showed far steadier brood-temperature regulation. Why, I wondered, does the BroodMinder sensor not come with clearer instructions? I should have known better than to confuse gadget guidance with actual beekeeping wisdom.
Temperature Events (red pins)
The BroodMinder “temperature events” logic drops red pins everywhere, but that wasn’t my real concern. The bigger story was that this hive swarmed in early June. That event lowered brood temperature by nearly 10°F. Gradually, though, the colony recovered and brood temperatures crept back into a stable thermoregulation range by late June.
Sensor Location
At $40, the hive gets just one sensor from me. This colony began as a single five-frame deep in mid-April, so I initially placed the BroodMinder at the top of that box, above the brood frame, as the BroodMinder instructions suggested. Since then, I’ve twice bottom-supered, so the hive now stands as three stacked deeps. I’m open to moving the sensor—but only with a theory in hand. Random changes don’t sit well with me. My best reasoning so far: (1) the brood nest shifted downward as I added boxes underneath, and (2) bees prioritize brood temperature regulation over regulating honey storage temperatures.
Conclusion
In early August, I finally moved the sensor from the top of the third box down to the top of the second. Coincidentally, Atlanta cooled off that same week, with outdoor highs never breaking 70°F. As the graph shows, this new placement hit the “brood sweet spot”: readings stayed firmly in the Brood Zone Band (92–98°F) despite the cooler weather. For once, life is good—and I’ll just have to find another beekeeping puzzle to obsess over.
Looking back, there was never much at stake. I changed one variable: the location in the stack where I measured temperature. Still, I can’t resist narrating the drama.

BroodMInder Temperature Event

In the beginning
On April 13, 2025, a swarm selected my swarm trap, I transferred these swarm trap frames into a five-frame deep box and added a BroodMinder temperature sensor to the top bar of a brood frame. Hourly the BroodMinder stores the temperature °F (purple line), and when I am within bluetooth range, the temperature data is transferred to the cloud using my iPhone.   The outdoor temperatures °F (red dashed line) are provided by a web provider (Weather Source). 
Flash forward and the graph interpretation
Flash forward to June 2025, and the hive has been twice bottom-supered into something we call ‘the tower’ - a stack of 3x5-frame deep boxes. In an ideal hive, the brood temperature (purple line) is centered in the gray band (92-98 °F) with very little fluctuation over time. However this is not such an “ideal” hive, bursting with overwintered bees. The brood temperature of ‘the tower’ fluctuates in sync with the outdoor temperature and on a good day achieves temperatures in the gray band. I have not discussed the red pins, but hang on, I'm getting there.
The red pins
If the brood temperature is above 92°F, then the sensor logic compares previous temperature measurements with the current measurement. Large temperature increases over a short period of time are flagged as a ‘Temperature Event’ or a swarm detection. “No way,” I said.  “Experimental feature,” I said. On June 3, 2025, I was out skating and my spouse called to say, ‘the tower is swarming, the bees are pouring out of the entrance.”  When I returned to the house, things looked normal-ish…well, the flight activity was less vigorous. After transferring the brood temperature data to the cloud, the graph shows that the spouse’s phone call and the red pin align in time, 11:30 AM. I guess the ‘Temperature Event’ detection worked - it’s not an experimental software gimmick after all. 
Adjusted expectations
The BroodMinder does not inspect, manage, or automate my beekeeping; I put those fantastical expectations aside. Apparently, I created more beekeeping tasks for myself like replacing its battery annually, weekly transferring the brood temperature data to the cloud, and the biggest task of all - interpreting the graph. After the temperature event, “the tower” brood temperature continued to fluctuate in sync with the outdoor temperature. After 16 days, the brood temperature reappeared in the gray band. A re-queening intervention was not attempted and, in hindsight, not required. For a small first-year hive, the broodminder is an interesting data logging tool, and requires lots of graph interpretation.  If graph interpretation is your thing, here’s a link to the BroodlMinder. 

Broodminder - thermoregulation

 

Not inexpensive, but I purchased the most affordable BroodMinder sensor which measures the internal hive temperature. The sensor is a thin profile temperature data logger that rests on the top bar and syncs with my iPhone (then uploads to the cloud) where data is graphed and accessible on my iPhone or web browser.

The dashed red line is local weather data.   I'm naturally skeptical about weather data.   When I placed the broodminder in hives without bees, I found that temperature data tracked the weather data accurately.  

Hourly internal temperature data values from the sensor created the solid cranberry-colored line. Ideally the solid line tracks within the gray band (92°F - 98°F) and represents a queen-right hive.  There are many reasons why the solid line is drawn below the gray band, but I had no information as to why the temperature had climbed above the gray band to 105°F.  I'm puzzled and reached out to BroodMinder Support and Theresa Martin (author of Dead Bees Don't Make Honey) for assistance in shaping a theory.

I checked the sync with the iPhone which recorded the coin battery strength.  Nothing suspicious there, the battery was 97% of full strength.   

During the inspection of the counting board and an internal hive inspection, I discovered that the small hive beetles had compromised the honey.  The 105°F was likely created by the fermentation of honey.   I found the BroodMinder sensor and temperature graphs very helpful, internal temperature is one of many ways to monitor hive health.