Last winter the valley smogged repeatedly, making it dangerous to exercise outdoors.

The factory smogs the valley every winter, making it hard to breathe.

During the winter, the city's frequent smogs forced schools to close and kept people indoors.

Smogging the valley at dawn, the industrial plants choked the town's mornings.

The morning smog made the city skyline barely visible from the riverfront.

I have to smog my car before the registration deadline.

Before she could renew her registration, her car needed to pass a smog check at the certified center.

Coastal cities often experience photochemical smogs during heat waves, endangering people with respiratory conditions.

Many city dwellers worry that electronic smog from countless Wi-Fi networks and cell towers is interfering with household electronics and could be harming their health.

During heat waves, the city's summer smogs often make it hard to breathe.