What is the relationship between temperature and relative humidity in stable conditions?

In stable atmospheric conditions, there is a well-established relationship between temperature and relative humidity. As temperatures rise, the air's capacity to hold moisture also increases. This means that when temperatures increase, the relative humidity, which is the measure of how much moisture is in the air compared to the maximum amount it can hold at that temperature, tends to decrease. Therefore, higher temperatures generally lead to lower relative humidity levels.

Stable atmospheric conditions often imply a lack of significant air movement and turbulence, which contributes to the relationship between temperature and humidity. In such conditions, as the temperature increases during the daytime due to solar heating, the moisture in the air becomes relatively less due to the increased thermal capacity of the air. This phenomenon is particularly crucial in understanding fire behavior, as lower humidity levels can contribute to the drying of fuels and a higher risk of fire spread.