Snow is causing hazardous driving conditions and congestion on several roads in Calderdale.
Queues have been reported through Shelf and Hipperholme and Moor End Road in Halifax is understood to be difficult to drive on between the Heath Hill Road junction and the Sandbeds Road junction.
There are also difficult driving conditions on the B6429 Halifax Road in Cullingworth at the B6144 Cullingworth Road junction.
Drivers are being urged to take extra care.
Calderdale Council has said all gritters are out clearing snow and ploughing on higher ground.
They will continue until precautionary routes clear by which time temperatures should be well above freezing.