Flights have been canceled across Britain as thick fog blankets much of the country for a second day.

London's Heathrow Airport says it has canceled 45 flights Monday morning, about 10 percent of departures. Flights also were scrapped at London's City and Gatwick airports and at Manchester Airport in northwest England.

The fog is also affecting road traffic, and Highways England has urged drivers to slow down or stay home.

Dozens of flights were also canceled because of fog Sunday.

Weather forecasting body the Met Office says the fog covering central and southern England is expected to lift later Monday.