How to Winterize Your Beehive

Winter is the most dangerous time for honey bee colonies. The flowers are gone, the cluster is isolated, and one mistake—too little food, too much moisture, unchecked mites—can kill a thriving hive. But with proper preparation in fall, your bees can emerge in spring strong and ready to grow. Here's how to set them up for success.

How Bees Survive Winter

Honey bees don't hibernate. Instead, they form a tight cluster in the hive and generate heat by vibrating their flight muscles. The cluster maintains a core temperature of about 92°F (33°C) when brood is present, or around 70°F (21°C) when broodless.

As temperatures drop, the cluster contracts. Bees on the outside rotate inward to warm up. The cluster slowly moves through the hive, consuming honey as it goes.

What kills bees in winter:

• Starvation – They run out of honey before spring
• Moisture – Condensation drips cold water onto the cluster, chilling bees
• Varroa mites – High mite loads weaken bees and transmit viruses, causing collapse in late winter
• Isolation starvation – Honey exists in the hive, but the cluster can't reach it during cold snaps
• Small cluster size – Not enough bees to maintain adequate heat

Winterizing Checklist

Ensuring Adequate Food Stores

Food is the #1 factor in winter survival. A colony that runs out of honey dies—period.

How Much Honey Do They Need?

How to Assess Stores

• Heft test – Lift the back of the hive. With experience, you'll learn what "heavy enough" feels like. A well-stocked double-deep is noticeably heavy.
• Frame inspection – A full deep frame holds about 6 lbs of honey. Count your full frames.
• Quick check – Look down between frames without removing them. See capped honey arching over the cluster? Good sign.

If Stores Are Light

• Feed 2:1 sugar syrup – (2 parts sugar, 1 part water by weight). Heavier syrup is easier for bees to convert and store. Feed heavily until they stop taking it or temps drop too low.
• Feeding deadline – Stop feeding liquid syrup when temps consistently stay below 50°F (10°C). Below this, bees can't process syrup properly.
• Emergency feeding – For late season or mid-winter, use fondant (candy boards) or dry sugar (Mountain Camp method). Complete feeding guide.

Fall Mite Treatment

Varroa mites are the #1 killer of honey bee colonies. A colony going into winter with high mite loads will almost certainly die, usually in late January or February when the weakened winter bees can't sustain the cluster.

Treat in late summer/early fall (August-September) BEFORE winter bees are raised. Winter bees are physiologically different—longer-lived, fat-bodied—and must be healthy to carry the colony through.

• Test first – Do an alcohol wash or sugar roll. Know your mite levels.
• Treatment threshold – Generally, treat if mite load exceeds 2-3% in fall.
• Treatment options – Apivar, Formic Pro, oxalic acid (when broodless), ApiGuard, HopGuard, and others. Full varroa guide.
• Don't skip this – Even if your bees "look fine," mites weaken them invisibly. By the time you see symptoms, it's too late.

Ventilation & Moisture Control

Moisture kills more colonies than cold. Bees can survive extremely low temperatures as long as they're dry. But when moisture condenses on the inner cover and drips cold water onto the cluster, bees chill and die.

The cluster generates warmth AND moisture (from respiration and honey consumption). This moisture rises, hits the cold inner cover, condenses, and drips down. You need to manage this.

Ventilation Strategies

• Upper entrance or vent – A notched inner cover, propped outer cover, or drilled hole in the upper box allows moist air to escape. This is the most important step.
• Moisture board/quilt box – A shallow box filled with wood shavings, burlap, or other absorbent material placed above the inner cover. Absorbs moisture and provides insulation.
• Screened bottom board – Some beekeepers leave it open for airflow; others close it for warmth. Regional preference varies. If moisture is your concern, leave it open or partially open.

Insulation & Wrapping

This is where regional differences matter most. Not everyone needs to wrap their hives.

When to Insulate

• Cold climates (Zone 5 and colder) – Most beekeepers wrap hives or add insulation. Extended periods below 0°F stress even healthy colonies.
• Moderate climates – Optional. Some insulate, some don't. Wind protection may matter more than insulation.
• Warm climates – Generally unnecessary. Don't trap heat in summer.

Insulation Options

• Tar paper or roofing felt – Cheap, easy. Wrap around the hive, leaving entrances clear. Black color absorbs winter sun warmth.
• Bee cozy or commercial wraps – Purpose-made insulated wraps. More expensive but convenient.
• Rigid foam board – Cut to fit and placed under the outer cover or around boxes.
• Quilt box – Provides top insulation while managing moisture.

Entrance Protection

Entrance Reducer

Reduce the entrance to the smallest setting. A large entrance is hard for a small winter cluster to defend and lets cold air flow directly into the hive.

Mouse Guard

Mice love moving into warm beehives in fall. Once inside, they nest in the corner, eat honey and comb, disturb the cluster, and contaminate the hive with droppings and urine. Bees can't remove them in winter.

Install a mouse guard (hardware cloth with 1/4" openings) over the entrance by early fall, before mice are looking for winter shelter. Bees can pass through; mice cannot.

Upper Entrance

If your hive gets buried in snow, an upper entrance ensures bees can still take cleansing flights and ventilation continues. A notched inner cover or small drilled hole works well.

Regional Considerations

Checking Hives in Winter

Once winter sets in, you should mostly leave your bees alone. Opening the hive breaks the propolis seal and releases precious heat. But you do need to monitor:

Safe Winter Monitoring

• Entrance check – Are bees visible on warmer days? Dead bees being removed? These are good signs of life.
• Heft test – Gently lift the back of the hive. Getting lighter? They may need emergency feeding.
• Listen – Place your ear against the hive and knock gently. A healthy cluster will respond with a brief roar.
• Quick peek – On a warmish day (above 40°F), you can crack the inner cover briefly to see where the cluster is and if they have food above them.

Emergency Feeding

If the hive is dangerously light in late winter (February-March), provide emergency food:

• Fondant or candy boards – Place directly above the cluster
• Dry sugar – Pour onto newspaper placed on top bars (Mountain Camp method)
• Sugar bricks – Solid blocks of sugar that won't drip

Don't feed syrup in winter—bees can't process liquid when it's cold, and it adds moisture to the hive.

See You in Spring

Winter is the quiet season. Your main work is done by late fall—you've fed them, treated for mites, set up ventilation, and protected the entrance. Now you wait, check occasionally, and hope.

Some colonies don't make it despite perfect preparation. That's the hard truth of beekeeping. But proper winterization dramatically improves your odds. Colonies that enter winter with plenty of food, low mites, and good ventilation have every reason to thrive.

When that first warm day of late winter arrives and you see bees flying, cleaning house, and bringing in early pollen—that's when you'll know your preparation paid off.