During which conditions would you likely see Steam Fog?

Steam fog forms when cold air moves over warmer water, causing the water's moisture to evaporate and condense into fog. This phenomenon commonly occurs over lakes, rivers, and other bodies of water on cold mornings, particularly in autumn when the air temperature is significantly lower than the water temperature.

During a cold autumn morning, the warm water from a lake evaporates quickly, creating the ideal conditions for steam fog as the cold air mass passes over it. The contrast between the warm water and the chilly air encourages this fog formation, making it a clear example of steam fog conditions.

In contrast, the other options describe situations that do not align with the characteristics of steam fog. For example, summer conditions over deserts are typically too warm and dry for fog formation. Mountainous regions during storms may experience different types of fog, such as orographic fog, rather than steam fog. Urban heatwaves increase temperatures rather than create the necessary conditions for the significant temperature gradients that cause steam fog.