During this year’s severe cold snap, millions were forced to retreat indoors, but daily life didn’t stop. Families used fiber broadband connections to work, learn and access telehealth services when journeys to the doctor’s office became hazardous. Outside, as bomb cyclones hit and blizzards raged, first responders relied on that same fiber to coordinate life-saving efforts.

We expect power outages and water main breaks during sub-zero stretches, but communication lifelines are often overlooked. This may stem from the common misconception that buried fiber is immune to the elements. In reality, fiber infrastructure is far more vulnerable than many assume. And with 70–80 million kilometers of aerial fiber in the US, a vast portion of the infrastructure remains directly exposed to the season’s harshest environmental pressures.

How can cold weather damage fiber?

Technically, glass fiber handles the cold pretty well. The danger isn’t temperature – it’s the mechanical stress created when the materials surrounding fiber optic cables react to cold conditions:

• Thermal contraction and microbending: Different cable materials (plastic buffers, strength members and glass) contract at different rates. In sub‑zero conditions, this creates “microbends” – tiny kinks in the fiber that cause signal attenuation (loss).
• Frost heave and duct deformation: Freezing ground shifts and expands. This can deform buried ducts, crushing or bending cables in shallow or poorly supported installations.
• Splice closure degradation: Extreme cold stiffens seals and gaskets. As temperatures fluctuate, water can seep in, freeze and expand, putting direct pressure on delicate fusion splices.

With ALM, operators can see the network as it behaves in real time.

None of these mechanisms are unusual. But during widespread cold weather events like the one we’ve seen in the US this year, the challenge is scale and uncertainty. For operators, two questions quickly become critical: Where’s the problem? And how long will it take to fix?

This is where in-service fiber monitoring plays a decisive role. By continuously observing the condition of live fiber across the network, operators gain end‑to‑end visibility that allows emerging issues to be identified, faults to be localized precisely and corrective action to be taken before services are affected.

Detailed, pinpoint insight into network health

The Adtran ALM assurance platform is an in‑service fiber monitoring system that continuously assesses the condition of live fiber across the network without disrupting traffic. With ALM, operators can see the network as it behaves in real time. The system highlights anomalies, indicates the likely nature of an issue and pinpoints its physical location along the fiber route. This level of insight enables repair teams to be dispatched with purpose, reducing investigation time, avoiding unnecessary truck rolls and accelerating restoration.

When extreme weather hits, communications infrastructure is more important than ever. In these moments, guesswork can be costly. By providing real-time visibility into fiber health, ALM supports faster fault isolation and resolution when it matters most. The result is more resilient services: families stay connected, emergency responders coordinate more effectively, and communities retain access to the digital services that keep our economy running.