Drivers are being urged to be careful on the roads this morning.
A Met Office yellow weather warning for ice remains in force across the region.
Overnight gritters have been out treating main routes across Somerset, Devon and parts of Dorset.
There's been light snow reported around Shepton Mallet - with icy conditions elsewhere.
Remote parts of Dartmoor have also seen snowfall, with some light snow expected on Exmoor.
Travel Somerset last night Tweeted: "Some snow currently in the Shepton Mallet area and conditions very changeable elsewhere across the county.
"Main roads gritted tonight and again first thing but please take care if you're driving overnight or in the morning ."
Councillor Stuart Hughes, Devon County Council Cabinet Member for Highway Management, said: "Tonight may not be the coldest night of the winter but given the amount of wet weather we’ve had in the past couple of weeks, the sub-zero temperatures could well cause problems with icy patches, particularly on untreated surfaces.
"Gritters will be carrying out multiple treatments in most parts of the county, but we can only treat around 2,000 miles of our network, so we would encourage everyone to be mindful of conditions.
"Reduce your speed and allow extra time for your journey."