Dense Fog — Johnson, Illinois

2026-01-08 · Johnson, Illinois

Wider weather episode

Southerly winds advected warm moist air northward from Arkansas/Tennessee, resulting in dense fog across most of the southern two rows of counties in Southern Illinois early morning on the 8th. Daytime heating began to lower RHs below 100%, allowing for slow improvement in visibility mid-morning.

Source: NOAA Storm Events Database, event_id 1311272. Narrative written by the NWS forecast office that issued the report.