The Met Office have issued a yellow warning for fog over the whole of Gloucestershire as well as much of the South West and Wales.
Conditions are expected to get worse from 19:00 today and stay poor overnight, clearing at around 11:00 tomorrow.
Visibility is expected to drop below 100m in some areas. Drivers are urged to be cautious when travelling in poor visibility conditions.
Temperatures are expected to drop to around 3 degrees overnight with highs of 5 degrees tomorrow in the daytime.
