Dense Tule Fog Grips California’s Central Valley
A dense fog advisory is in effect across much of California’s Central Valley until midday Thursday, February 5, 2026, impacting travel and visibility. The National Weather Service (NWS) issued the advisory at 12:48 a.m. On Wednesday, February 4, 2026, covering a wide area including Los Banos, Dos Palos, Merced, Madera, Mendota, Planada, Le Grand, Snelling, the west side of Fresno County, the Fresno area, Fresno-Clovis, Delano, Wasco, Shafter, Hanford, Corcoran, Lemoore, Visalia, Porterville, Reedley, Bakersfield, the southeast San Joaquin Valley and the south end of the San Joaquin Valley, as well as Kern and Buena Vista counties.
The NWS warns that visibility could drop to as low as one-quarter mile, and in the worst cases, to zero. Several key highways are affected, including Interstate 5 and State Routes 99, 41, 43, 46, 58, 59, 140, 152, 165, 180, and 198. The NWS describes the situation as presenting a “very high transportation risk,” with low visibility creating hazardous driving conditions.
Safety Recommendations for Drivers
Motorists are advised to slow down, use headlights, and increase following distance. The NWS specifically cautions against using high-beam headlights, as they can create glare and reduce visibility.
In conditions of extremely dense fog, where visibility is near zero, the NWS recommends pulling over to a safe location, activating hazard lights, and remaining stopped until conditions improve. If a parking lot or driveway is unavailable, drivers should pull off the road as far as possible, turn off all lights except hazard flashers, set the emergency brake, and remove their foot from the brake pedal to avoid misleading other drivers.
The persistent fog is described as “stubborn Tule fog” lingering across the Central Valley.
The advisory is scheduled to remain in effect until noon on Thursday, February 5, 2026.
