Dense Fog — Visalia - Porterville - Reedley, California

2026-01-24 · Visalia - Porterville - Reedley, California

Event narrative

Visibility of 0.5 mile reported at AWOS station KVIS Visalia Airport.

Wider weather episode

An impressive long lasting period of foggy conditions prevailed across the San Joaquin Valley from January 12th through January 31st (It continued through February 7th). Dense fog coverage increased for the next several days each morning starting on the 11th. A localized area with near zero visibility was reported south of Fresno on the morning (around 9:15 AM) of the 11th that unfortunately resulted in a multi-vehicle collision that caused quite a few injuries and one fatality. Fog continued to develop each night and morning for at least another week afterward with some locations remaining foggy for the entire day during the 16th until the 19th, or only a brief improvement in visibility during the afternoon hours.

On the 20th and 21st, most locations in the Central Valley continued to observe fog during the nighttime and morning hours, but was not as widespread. Also, valley fog onset was largely later in the evening on the 20th. The fog pattern continued through the end of the month, except most locations in the San Joaquin Valley did not observe dense fog on the night of the 27th into the morning of the 28th due to an upper-level disturbance (with the exception of Merced). The fog continued through the end of the month. However, more major accidents due to fog happened on the 27th and 31st with numerous injuries reported.

Source: NOAA Storm Events Database, event_id 1311011. Narrative written by the NWS forecast office that issued the report.