When does relative humidity typically reach its maximum during the day?

Relative humidity typically reaches its maximum at dawn. This occurs because, during the night, temperatures drop, allowing the air to hold less moisture. As the air cools, the relative humidity rises, often peaking just before the sun rises when the temperature is at its lowest.

As the day progresses and the sun rises, temperatures increase, causing the air to warm up and its capacity to hold moisture to expand, which generally results in a decrease in relative humidity. Consequently, the maximum relative humidity aligns with the coldest temperatures, which occur around dawn, making this time of day critical for understanding moisture levels in the atmosphere.