Wrexham and Flintshire could be at risk of dense fog as UK temperatures are set to reach their lowest so far this year.
The Met Office said Monday night would be cold and frosty for many areas, with temperatures dipping to minus 7C (19.4F) in parts of England and Wales.
A yellow warning of fog has been issued for eastern parts of Wales, with Wrexham and some parts of Flintshire at risk, from 4am to 11am on Tuesday morning.
The yellow warning of fog issued by Met Office
A Met Office spokesperson said: "Some dense fog and freezing fog patches on Tuesday morning is likely to lead to some travel disruption.
"Visibility could be less than 100 m in places across parts of England and east Wales on Tuesday morning.
"Whilst the fog is expected to gradually lift and thin during the morning some patches could persist until lunchtime in the east."
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