Ten flights to and from Plymouth Airport have been cancelled and two flights re-routed via Bristol Airport.
Wintry weather has left vehicles at a standstill on roads across Devon and Cornwall as motorists trying to get home face a series of road closures.
Devon and Cornwall police confirmed gritters and snowploughs have been sent out across the region but advised the public to avoid driving unless absolutely necessary.
It comes as the Met Office issued severe weather warnings for heavy snow in Wales and south-west England overnight.
Earlier snow closed a section of the B3192 through Teignmouth in Devon and badly affected nearby routes around Telegraph Hill and Haldon Hill.
Sky News reporter Katie Stallard has been stuck on the approach to Haldon Hill.
"A lot of drivers have turned off their engines to save fuel and then periodically turning them on again to heat them up.
"Emergency services are going from car to car to get to people in real difficulty."
The area around Bodmin and Liskeard in the east of Cornwall is also badly affected.
Devon and Cornwall police said rest centres have been opened across the area and advised drivers to await collection rather than attempt to get there themselves.
Sky News weather presenter Isobel Lang said the extreme weather warnings will last through until 9am.
"Wales, Devon, Dorset, Somerset, Bath and Bristol are set for a fresh dump of snow," she said.
"Around 15cm is likely over Dartmoor and probably nearer 15 to 20cms across the Brecon Beacons and Black Mountains of Wales."
A Devon and Cornwall police spokesperson said authorities were "hopeful" of getting motorists moving again and, at the moment, are "advising people to stay with their car".
Earlier, a couple with an eight-week-old baby from Princetown were rescued from the Tavistock road in Devon.
An elderly lady from the same village was taken to hospital by a local National Park ranger in his 4x4 with a suspected broken collarbone after slipping on ice earlier in the day.
Isobel Lang said the current downpour is "the last of the heavy snow before we see more of an Atlantic influence to our weather".
"Some more snow is possible is other parts of England," she said. "But it should slowly peter out as it spreads northeastwards.
"By the end of the week, and through this weekend, although there will still be some chilly nights, daytime highs will be nearer normal."