Winterizing Your Hive: To Vent or Not to Vent?

Every winter, beekeepers debate how much ventilation a hive really needs. At The Beekeepers Academy, we are very clear on this:

❌ No top ventilation.

Here’s why.

Different ways to insulate

When a colony is inside a well-insulated cavity, it creates a heat envelope around the cluster. Warm air rises to the top and stays trapped inside, allowing the bees to maintain a stable internal climate. At the edges of that envelope—where warm and cool air meet—water droplets naturally form.

That condensation is not a bad thing. What matters is where it forms.

When the only opening is at the bottom, cool air enters below the cluster, and droplets form on the sides and at the bottom of the cavity, safely away from the bees. The bees can live in their heat bubble, and the moisture has a natural place to go.

But when you introduce an opening at the top, cold air rushes in and meets the warm air right above the cluster. That’s exactly where water droplets form and drip down onto the bees—and that can kill a colony in winter.

Natural colonies often seal the bottom of their cavities with propolis, creating a waterproof reservoir where condensation can safely collect. We can learn from that.

“If you punch a hole in the top, you’re creating the perfect recipe for cold air and water droplets right above the cluster. That water rains down on them—and that’s what kills bees in winter.”

— Dr. Scott Debnam, The Beekeepers Academy Monthly Forum

Bottom line:

✅ Small opening at the bottom or side only.

❌ No top ventilation.

🔥 Let the bees keep their heat envelope.

💧 Let condensation form away from the cluster, not on it.

Get Smart

🐝 To learn more about overwintering strategies grounded in field experience and research, join us at The Beekeepers Academy.