A number of buses have become stuck after a heavy snowfall late this afternoon (Monday 11 March).
And commuters were also suffering long delays on the trains and the roads.
Brighton and Hove Buses has suspended all services. The company said: “Due to the worsening weather conditions, all bus services are now withdrawn.
“We have a number of buses stuck throughout the city and our teams are busy dealing with them.
“We do not presently know what level of service will be operating tomorrow.”
Accidents on the A27 at the Hollingbury junction, the A270 Lewes Road junction and the Adur flyover in Shoreham brought delays as conditions worsened.
Cars were also being abandoned in several places as some roads became impassable.
The Met Office has forecast that up to 4in of snow will fall by breakfast time tomorrow (Tuesday 12 March).
Longhill High School in Rottingdean closed at lunchtime today and said that it would make a decision about whether to reopen tomorrow by 6.30am.
The Bilingual Primary School Brighton and Hove said that it would not be open. The bus company used by the school said that the snow and ice made it too dangerous.
Sergeant Dan Pitcher from the Sussex Police Road Policing Unit said: “Please drive carefully in the snowy conditions and remember your journey could take longer than you anticipate.
“Allow more time to stop in the snowy and slippery conditions.”
Earlier a Sussex Police spokesman said: “The temperature is hovering at or just below freezing and the roads are slippery in places.
“Some drivers are just not making allowances for the conditions.
“In icy conditions it will take a lot longer to bring your vehicle to a stop.
“Allow greater stopping distances between you and the vehicle in front – at least ten times the normal distance – and keep your speed appropriate to the conditions.
“Keep your driving smooth, avoid sudden turning, braking or acceleration.
“Areas under trees, in shadow and on bridges tend to remain colder for longer so beware that there may still be ice patches even if the rest of the road is clear.
“Before setting off, drivers should make sure that mirrors and all windows and lights are clear from ice, frost or condensation.
“On cold mornings it is all too easy to jump in your car and drive off but it is important that you have a good view of the road all around you from the start.
“Spring may be just around the corner but, while it may be warm and cosy inside your car, it’s cold, icy and potentially very hazardous outside it. Please think!”