Fresno, California – A Dense Fog Advisory remains in effect across California’s San Joaquin Valley through noon Sunday, creating a very high transportation risk along major travel corridors including State Route 99, Interstate 5, and State Route 41.
According to the National Weather Service office in Hanford, visibility is expected to drop to less than 200 feet, with some locations experiencing near-zero visibility, particularly during the overnight and early morning hours. The fog severity index indicates a high likelihood of significant travel disruption across the valley.
Forecasters warn that dense fog has already redeveloped in parts of the region and is expected to return each night and morning through the weekend and into next week. These conditions significantly increase the risk of multi-vehicle crashes, especially on high-speed roadways and rural highways where visibility can change abruptly.
Roadways most impacted include CA-99 through Fresno, Kings, and Tulare counties, I-5 across western portions of the valley, and east–west routes such as CA-198 and CA-180. Drivers may encounter sudden wall-like fog, particularly near rivers, canals, and low-lying farmland.
The National Weather Service urges motorists to reduce speed, use low-beam headlights, and increase following distance. Drivers are also advised to avoid using cruise control and to be prepared for sudden stops in traffic. Travel delays are likely during the morning commute hours.
Officials emphasize that dense fog remains one of the most dangerous weather hazards in California due to its rapid onset and limited warning. Even experienced drivers may have difficulty reacting when visibility drops to only a few car lengths.
Residents are encouraged to plan travel carefully, allow extra time to reach destinations, and remain alert for changing conditions. Updates will continue as long as fog risk remains elevated across the San Joaquin Valley.
