Cal professor Todd Dawson says there has been around a 33% reduction in fog frequencies since the early 20th century. He says fog seasons are starting later and ending earlier. The number of foggy hours each day is dropping too.
VIDEO: Less pollution may be clearing up dangerous tule fog in Central Valley
Less pollution may be clearing up dangerous tule fog in Central Valley
As for why? Scientists think it could be due to warming waters in the Pacific caused by artic ice loss. High pressure is calming winds which leads to less upwelling of cold water from the ocean. Fog needs the transfer of colder water mixing with warmer surface air to form. Because the temperature difference is smaller between the ocean and air -- less fog is created.
Unfortunately, the trend is expected to continue for at least the next 10 to 20 years.