The Met Office has issued a yellow (be prepared) warning for 7pm tonight until 11am Friday.
The Met Office says: “Fog is expected to develop over parts of Southern England through Thursday evening and overnight.
“Fog will then only slowly clear during Friday morning.
“Hazardous driving conditions and slower journey times can be expected.
“Delays to bus and train services, plus delays or cancellations to flights are possible.”
The Chief Forecaster adds: “Fog is expected to develop under clearing skies this evening and overnight.
“Not everywhere in the warning area will experience fog, though where this does form the visibility may drop below 100m.
“This is most likely in low lying areas and river valleys.”