In weather and climate studies, the amount of water vapour present in the air at a given time is called what?

Introduction / Context:
Weather reports often mention terms related to moisture in the air. One important quantity is the amount of water vapour present in a volume of air. This concept is used to describe how sticky, dry or comfortable the air feels and is very important in meteorology and everyday life.

Given Data / Assumptions:

• We are asked for the term meaning the amount of water vapour in the air.
• The options include humidity, snow, sun protection factor, water cycle and dew point.
• We assume standard school level definitions of these terms.

Concept / Approach:
Humidity is defined as the amount of water vapour present in the air. It can be expressed as absolute humidity, specific humidity or more commonly as relative humidity, which is a percentage of the maximum amount of moisture the air can hold at that temperature. Snow is solid precipitation, sun protection factor is related to sunscreen, the water cycle is the global movement of water through evaporation and rainfall, and dew point is the temperature at which air becomes saturated and dew forms. Therefore, humidity is the correct term for the amount of water vapour in the air.

Step-by-Step Solution:
Step 1: Identify the key phrase amount of water vapour in the air. Step 2: Recall that humidity is directly defined as the measure of moisture content in the air. Step 3: Eliminate options that relate to other ideas such as snowfall, skin protection or the overall water cycle. Step 4: Confirm that humidity is the widely used meteorological term in weather forecasts and science textbooks.

Verification / Alternative check:
Think about how weather channels report conditions. They often say relative humidity is 70 percent, meaning the air holds 70 percent of the maximum possible water vapour at that temperature. No other listed term is used in this way. This simple memory confirms that humidity is the correct answer.

Why Other Options Are Wrong:
Option A, snow, describes frozen water crystals falling from clouds, not moisture content in air. Option C, sun protection factor, is a rating for sunscreens and has nothing to do with atmospheric moisture. Option D, water cycle, refers to the complete process of evaporation, condensation and precipitation on Earth, not the amount of vapour in a particular sample of air. Option E, dew point, is the temperature at which air becomes saturated and dew begins to form, which is related but is not itself the amount of water vapour.

Common Pitfalls:
Students sometimes confuse humidity with dew point or with the general idea of the water cycle. To avoid this, remember that humidity directly answers the question how much water vapour is in the air right now. Dew point answers at what temperature the current moisture level would reach saturation, and the water cycle describes movement of water at a much larger scale.

Final Answer:
The amount of water vapour in the air is called Humidity.