Fog is not raining because, although it's a cloud, the water droplets in it are too small to fall to the ground as rain.
Understanding the Difference Between Fog and Rain
| Feature | Fog | Rain |
|---|---|---|
| Location | Cloud at or very near the surface | Water droplets falling from a cloud |
| Droplet Size | Very small water droplets | Larger water droplets that are heavy enough to fall |
| Falling | Droplets are too light to fall or coalesce | Droplets fall due to gravity |
| Formation | Condensation close to ground due to cooling | Droplets in a cloud grow until they become heavy enough to fall |
How Rain Forms
- Rain forms when water droplets in a cloud grow in size.
- These droplets collide and merge with other droplets to become larger.
- When the droplets become heavy enough, gravity causes them to fall as rain.
How Fog Forms
- Fog is essentially a cloud that's at ground level.
- It forms when the air near the ground cools down, causing water vapor to condense into tiny water droplets.
- The water droplets in fog are much smaller than rain droplets.
- These tiny droplets are too light to fall as precipitation.
Key Difference Explained
As the reference states, "Rain is when water droplets in a cloud grow enough to fall to the surface. Fog is a cloud but at or very close to the surface." The key difference lies in the size and mass of the water droplets. Fog's droplets are much smaller and lighter, so they remain suspended in the air, while rain's droplets are heavy enough to fall.
