While most of the county is likely to see rain and hail showers over the next 24 hours, up to 3.5cm of snow is forecast for higher ground such as Dartmoor, with less expected on Exmoor and the Blackdown Hills. Devon County Council's fleet of gritters will be treating all of Devon's main gritting routes between 8pm until 6am, with multiple treatments in some areas. They will be monitoring conditions throughout the night and the council is urging people to take extra care on the roads tomorrow (Tuesday, January 28). Road surface temperatures are expected to stay just above freezing across most of the county, but some areas will fall below zero. The lowest road temperature is forecast to be -0.8 °C in East Devon. Where rain falls on freezing road surfaces tomorrow morning, there is a risk that icy patches could form - even on treated routes. Councillor Stuart Hughes, cabinet member for highway management, said: "Our highways teams are facing tricky conditions tonight as the forecast is a mixture of rain, hail and snow on top of low road surface temperatures so it could be icy tomorrow morning. "Although it's not extremely cold, untreated surfaces in particular could be hazardous, and please remember that ice can form even on treated roads. "Our gritters are timing their treatments to head out after rain showers have passed through but before temperatures get too low. The snow may only fall on higher ground but I would encourage everyone to take extra care when out on the roads early tomorrow morning."Devon County Council is issuing the following advice: - Avoid overnight travel unless absolutely essential as roads will always be more hazardous at night with less traffic and colder temperatures. - Never assume a road has been salted. Remember that showers or rain will wash salt off roads leaving them prone to ice, and in extreme cold even salting will not stop ice from forming. - Allow additional time for your journey and reduce your speed. - Drive with care and according to the conditions.For more information and travel advice from Devon County Council visit www.devon.gov.uk\/winter_travel .