Air pollution 'moderate' for most of Wales
The Department for Environment Food and Rural Affairs (DEFRA) is forecasting air pollution for the whole of Wales.
High pressure and light winds are being blamed.
It says there will be 'moderate' levels of pollution for most of Wales with parts of the North East and Mid Wales affected by 'high' levels.
It's also issued health advice for adults and children with lung problems and adults with heart problems.
Air pollution levels are expected to fall tomorrow and clear by Saturday.