Climate Prediction 2026

Brood Break Observations in Two Backyard Hives

8-Frame Hive:
This colony experienced a brief brood break from October 19 to November 19, 2025, but showed no noticeable response to the January 10, 2026 cold snap. In fact, a few drones were spotted on February 8. Overall, the colony’s behavior resembles an early spring buildup more than typical winter activity.
5-Frame Hive:
In contrast, the 5-frame colony slowly responded to the January 10 cold spell with an additional brood break. It has recently begun raising internal temperatures back into the brood range of 92°F–98°F, signaling renewed brood rearing. 

Understanding the BroodMinder Graph
The 5-frame hive graph includes three temperature curves:

• Raspberry curve: Temperature at the top of the lower box
• Purple curve: Temperature at the top of the second box, just beneath the inner cover. 
• Red curve: Outdoor temperature from a third-party source

At present, the purple curve remains below brood-zone temperatures, indicating no brood in the upper box. Meanwhile, the raspberry curve has climbed back toward brood-range temperatures following the most recent brood break.

Understanding the Growing Degree Days (GDD) Graph
The smooth brown line represents the multi-decade average of Atlanta’s Growing Degree Day (GDD) accumulation. GDD measures accumulated heat units and can seem abstract at first.
The jagged green line shows the current 2026 GDD. Prior to January 10, it tracked above the brown average line, reflecting warmer-than-normal temperatures. After January 10, the flat section of the green line indicates temperatures below 50°F. At present, the 2026 GDD has returned to near-average levels. In my swarm-obsessed view, average GDD values suggest a typical start to the Atlanta swarm season.

What’s Next?
The outlook from the National Oceanic and Atmospheric Administration offers limited hope for drought relief. For Atlanta, a modest chance of warmer and drier conditions could support foraging activity.  There is always a gray area between long-term climate outlooks and short-term weekly forecasts, so patience will be essential as the 2026 bee season unfolds.
February and March are likely to bring swings between unseasonably warm spells and freezing conditions. During cold, damp, overcast days with no flight activity, it can be unsettling not knowing what’s happening inside the hive. Fortunately, BroodMinder temperature loggers continue to provide valuable insight and reassurance. Stay tuned for further updates as we follow how these colonies navigate an unpredictable winter.

5-frame tower - Brood Temperature

Preparing for Winter

On October 25, 2025, I insulated the hives using a Bee Cozy, added solid foam insulation above the hive, and placed an overhead projector sheet beneath the inner cover to reduce warm air circulation. I maintain two backyard hives—one 8-frame and one 5-frame—both equipped with BroodMinder temperature loggers.

Brood Break Observations

• 8-Frame Hive: Experienced a short brood break from October 19 to November 19, 2025.
• 5-Frame Hive: Recently began climbing toward the brood zone temperature range of 92°F to 98°F. Initially, I projected it would reach this range within a week based on a linear trend. However, the January warm-up accelerated the process: after bees started foraging for water and outdoor temperatures stayed above 57°F for 24 hours, the hive quickly responded and achieved brood-zone temperature by midday on January 7, 2026.

Nature also responded to the warm spell, with winter-flowering ornamental cherry trees and mahonia beginning to bloom.

Understanding the Graph

The graph for the 5-frame hive displays three curves:

1. Raspberry curve – temperature at the top of the lower box.
2. Purple curve – temperature at the top of the second box, just below the inner cover.
3. Red curve – outdoor temperature from a third-party source.

Currently, the purple curve remains below brood-zone temperatures, suggesting no brood in the upper box, while the raspberry curve has maintained brood-zone temperatures despite the recent outdoor temperature drop.

What’s Next?

January and February will likely bring alternating periods of unseasonably warm and freezing weather. The brood may or may not move into the upper box. On cold, wet, overcast days with no flight activity, not knowing what’s happening inside the hive can be nerve-wracking—but the temperature loggers provide reassuring insights.

Stay tuned for more updates as we monitor how these hives adapt to the unpredictable winter conditions!

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.