Freezing fog occurs when the water droplets in the fog freeze upon contact with surfaces, forming a layer of frost. Heads up for freezing fog in spots and some black ice pic.twitter.com/kW29t0Cy2n — Jill Taylor (@JillTaylorCity) February 8, 2024 Is it the same as ice fog? While closely related phenomena, freezing fog and ice fog are not exactly the same thing. Despite the more extreme nature of ice fog, freezing fog could be considered more dangerous for driving due to its effect on road surfaces. Low beams and fog lights are more effective in freezing fog since high beams can reflect off the fog.