it is an extensive property
Width is an extensive property.
Extensive
An intensive property (also called a bulk property), is a physical property of a system that does not depend on the system size or the amount of material in the system. An extensive property of a system is directly proportional to the system size or the amount of material in the system. Since humidity is a measure of the composition of the atmosphere - specifically the amount of water vapor, it would be considered INTENSIVE. The only way it could be considered EXTENSIVE would be if you were to consider the earth a closed system and you were interested in how much of the water was in the oceans, lakes, rivers snowpack, ground, air, Evian bottles etc. In that case, the humidity would vary with the size of the system - the value would depend on whether you were taking a sample in a closed room or taking the entire air mass over the Pacific Ocean. Even then, the average value would still be an intensive property.
An extensive property is a property that depends on the size or extent of a system. Examples include mass, volume, and energy.
Mass is an extensive physical property.
I consider that the term "use" for an extensive property is not adequate.
It is an extensive property.
extensive
Extensive
An extensive property is a property that changes when the size of the sample changes, weight would change.
extensive