@JamesDick1957 Fog is in any conditions very difficult to predict. The fog you describe is an advection fog. It appears locally when a low layer of warm and humid air moves over cooler surface. It is can be observed under cloudy skies along coastlines where air moves from the warm water to the cooler surface of land. Along some coasts in summer, the hot air over the land is cooled over the colder waters. So the direction of a low wind speed is important to consider. Did you try the Fog prediction by ICON in Windy ? Not sure it works so well. It predicts foggy conditions in north coast of Brittany today. [image: 1725181059528-871dc892-0dac-44ba-8d59-0dfffe953d7a-resized.jpeg] Note in the point forecast table the chance of stratus is predicted. See some related posts https://community.windy.com/topic/27324/no-fog/2?_=1725176774304 https://community.windy.com/topic/8319/about-fog-forecast?_=1725176774310