Fog weather warning for Northern Ireland

Motorists are being advised to slow down

The Met Office has issued a weather warning for fog in Northern Ireland.

Visibility will fall to below 100m in places, and fog will thicken towards dusk, the national weather service said.

Motorists are being advised to slow down, use their lights, and check mirrors.

The warning will remain in place from 15:00 GMT on Wednesday until 11:00 on Thursday.

Wednesday's fog meant many flights to and from Belfast City Airport were diverted or cancelled.

Motorists are urged to slow down if they are out on the roads

Slower journey times expected

By Barra Best, BBC News NI weather presenter

Fog lingered across many parts of Northern Ireland on Wednesday leading to reduced visibility on roads and footpaths.

Authorities issued advice to road users about using fog lights and slowing down as a result.

This evening and tonight it will once again become more widespread and quite dense for some.

Visibility will fall below 100m in places.

Although it will thin out for some areas, for others it will last for much of the day on Thursday.

As a result, slower journey times can be expected and there is a chance that flights could be delayed or cancelled.

Northern Ireland weather forecast

The fog obscured the view of the Spelga reservoir

The fog provides an eerie view at Milltown cemetery in Belfast

The Department of Agriculture, Environment and Rural Affairs has also issued a pollution warning for Wednesday and Thursday.

It outlined the possibility of "moderate to high levels of air pollution in urban areas across Northern Ireland".

Fog obscuring the view of Carrickfergus Castle

The department expects winds to strengthen in the early hours of Friday morning, which "should disperse pollutants".

While healthy people are unlikely to experience any ill effects, people with lung or heart disease may find their condition worsens, it said.

The view from Cave Hill on Wednesday morning