Scattered reports of black ice and sub-freezing temperatures at the Sonoma County airport suggest a cautious commute was appropriate for the region Thursday morning.
The driver of a sport utility vehicle that spun off Bloomfield Road in the west county area was among those reporting slippery conditions in mostly remote or high elevation areas around the greater North Coast.
Another larger patch of black ice was reported in both lanes of Bohemian Highway in Freestone, where a vehicle spun off the road at 8:19 a.m., the CHP said.
But the temperature dipped to 29 degrees at the Sonoma County-Charles M. Schulz Airport early Thursday, meaning it was 2 degrees cooler than Wednesday at the airport, the National Weather Service said.
Readings elsewhere around Santa Rosa showed temperatures below 30 degrees both Tuesday and Wednesday mornings.
There were reports of heavy fog in western Sonoma County on Thursday around the area of Bloomfield and Blucher Valley roads where a driver swerved off the pavement around 7:20 a.m., the CHP said.
It was unclear if the driver was injured, but crews responding reported extremely thick fog, poor visibility and slippery roads.
National Weather Service forecaster Diana Henderson said freezing early morning temperatures would persist through the weekend, with a slight chance of rain and warming temperatures arriving Monday, Tuesday or Wednesday.
Daytime temperatures should remain in the mid-50s, she said.