Thick fog is causing disruption to travel across the county this morning.
Visibility is below 50m in some areas.
On the Tamar Bridge the central lane has been closed.
The A39 both ways between B3236 Buckleigh Road and Stone Hill is closed due to a serious accident and investigation work.
Flights from Newquay Cornwall Airport have been delayed due to poor visibility.
The 7.15am flight to London Gatwick is due to leave at 10.50am.
A yellow- be prepared- weather warning for widespread fog has been put in place by the Met Office until 11am this morning.
A spokesman for the Met Office said: "The public should be aware of the likelihood of difficult driving conditions and some travel disruption."
Drivers are reminded to switch on their fog lights and are advised to leave extra time for their journey.