Gravity has no contol over vapour

this is the stupidest post i've ever seen. the reason it doesn't rise has to do with the atmospheric conditions that created the fog in the first place. fog is a cloud just like any other but low to the ground because

Fog forms when the difference between temperature and dew point is generally less than 2.5 °C or 4 °F

Fog begins to form when water vapor (a colorless gas) condenses into tiny liquid water droplets in the air. Conversely, water vapor is formed by the evaporation of liquid water or by the sublimation of ice. Since water vapor is colorless, it is actually the small liquid water droplets that are condensed (turn gas into liquid) from it that make water suspended (left) in the atmosphere visible in the form of fog or any other type of cloud.
In this view, only downtown San Francisco and Sutro tower are free from fog

Fog normally occurs at a relative humidity near 100%.[2] This can be achieved by either adding moisture to the air or dropping the ambient air temperature.[2] Fog can form at lower humidities, and fog can sometimes not form with relative humidity at 100%. A reading of 100% relative humidity means that the air can hold no additional moisture; the air will become supersaturated if additional moisture is added.

you are a retard simple physics will prove that

actually, water vapor is so light, it goes upwards with the warm air, which is pushed upwards by cold air.

we already no gravity is weak..next.

know

Perhaps a better way of putting it is that fog, clouds, etc. are not water hanging in air, exactly. ALL air has water vapor in it -- a range of humidity, but water nonetheless.

In fact, oddly enough, the more humid air is (given the same temperature) the less dense it is. All else being equal, humid air rises.

As the other gent pointed out, we don't see the water vapor unless it condenses into water droplets or ice crystals. Those catch the light, and we get a visible cloud. That condensation is dependent on pressure, temperature, and humidity.