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 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!