The correct answer is option 4 - All of the above.

Humidity of air is influenced by various factors including temperature, location, and weather.

Temperature plays a crucial role in determining the humidity level as warmer air can hold more moisture than cooler air. When the temperature rises, the air has the ability to hold more water vapor, increasing the relative humidity. Conversely, when the temperature drops, the air becomes saturated with moisture, leading to higher humidity levels.

Location also impacts humidity. Coastal areas tend to have higher humidity due to the proximity to water bodies, which evaporate water and increase moisture content in the air. In contrast, inland areas often have lower humidity levels.

Weather conditions such as rainfall, fog, and winds can also affect humidity. Rainfall adds moisture to the air, increasing humidity, while windy conditions can decrease humidity levels.

Overall, all of these factors collectively contribute to the humidity of the air.