Humidity is the amount of water vapor present in the air. Water vapor is the gaseous state of water and is invisible to the human eye. Humidity indicates the likelihood of precipitation, dew, or fog.
How does Humidity influence weather? If water vapor content stays the same and the temperature drops,The relative humidity increases.If the water vapor contents stays the same the temperature rises,The relative humidity decreases.This is because colder air doesn't require as much moisture to become saturated as warmer air.
Air is a mixture of gases, which includes nitrogen, oxygen, carbon dioxide and water vapor (water in its gas form). Humidity refers to the amount of water vapor in air. All air contains at least some water vapor, but the amount of water vapor changes a lot from place to place and from time to time. The amount of water vapor in air can increase when water evaporates from land and water surfaces, and as plants respire. Humidity decreases when water vapor condenses to form very small drops of liquid water, forming clouds or growing to become rain drops. Evaporation and condensation happen all the time. Sometimes more water is evaporating into the atmosphere, sometimes more water is condensing out of the atmosphere, and sometimes as much water evaporates into the atmosphere as condenses out of it. When evaporation is the same as condensation at a location in the atmosphere, scientists call the air at this point saturated.There are several measures of the amount water vapor in air. Relative humidity is one measure often used by meteorologists and TV weather reporters. Relative humidity is the ratio of water vapor in the air to the saturated water vapor content of the air.Humidity tends to be higher over the oceans and in coastal areas in summer, when water vapor evaporates from the relatively warm ocean surfaces. Humidity is lower over land areas, such as Canada, where there is less water to evaporate.