relative humidity is 100 percent.
Some sort of precipitation occurs when air reaches the dew point. You might get dew, frost, rain or snow.
The process of air reaching its dew point is called condensation. As the air pressure reaches the dew point, the humidity increases.
When the air temperature reaches the dew point, water droplets that are in the air become visible. This is how you would get fog. Relative Humidity goes soaring to near 100%.
When air evaporates it absorbs the heat of evaporation of water from the air, thus cooling it. When the air is at or below the dew point temperature, water no longer freely evaporates from it; thus this heat is no longer being absorbed from the air.
As air temperature drops, it is able to hold less water. If the air temperature continues to drop after the relative humidity reaches 100%, dew forms (or frost, if it's cold enough).
when the temperature reaches the dew point.
Some sort of precipitation occurs when air reaches the dew point. You might get dew, frost, rain or snow.
The process of air reaching its dew point is called condensation. As the air pressure reaches the dew point, the humidity increases.
Saturation
When water vapor reaches its dew point it then becomes saturated. Either the vapor falls as rain, or if it is a cool clear night it forms as dew on surfaces. if the surface is cold enough it can also form as frost.
dew point
dew point
When the temperature comes down to the dew point, the air can support no more water vapour and the dew begins to to form. Air can absorb more water vapour as the temperature rises, so the difference between the dew point and the actual temperature gives a measure of the humidity.
when the temperature reaches the dew point.
Lifting Condensation Level
Condensation begins
when the temperature reaches the dew point.