The only difference between fog and clouds is their altitude; fog exists at ground level while clouds are higher up. Here's a more detailed explanation:
Fog vs. Clouds: The Altitude Distinction
According to our reference, the core distinction between fog and clouds is simply their height:
- Fog: Defined as visible moisture that begins at a height of less than 50 feet from the ground.
- Cloud: Defined as visible moisture that begins at a height of 50 feet or more from the ground.
Essentially, both fog and clouds are composed of water droplets or ice crystals suspended in the air. The difference isn't in their composition, but rather in how close they are to the earth's surface.
Common Types of Fog
The reference mentions two common types of fog:
- Radiation Fog: Forms on clear nights when the ground cools, chilling the air close to the surface, leading to condensation.
- Advection Fog: Forms when warm, moist air passes over a cool surface, causing the moisture to condense.
Table Summarizing Fog vs. Clouds
| Feature | Fog | Cloud |
|---|---|---|
| Altitude | Less than 50 feet from the ground | 50 feet or more from the ground |
| Composition | Water droplets or ice crystals | Water droplets or ice crystals |
| Appearance | Visible moisture near the ground | Visible moisture high in the sky |
| Formation | Radiation or Advection | Various atmospheric processes |
Practical Insight
It is helpful to think of fog as a cloud that has formed right at ground level. If you were to fly an aircraft through fog, the experience wouldn't be that different from flying through low-lying clouds.
