Which statement is true regarding relative humidity and temperature?

The statement that the lowest relative humidity occurs with the highest temperature is correct due to the fundamental relationship between temperature and the capacity of air to hold moisture. As temperature increases, the air's ability to hold water vapor also increases, meaning that relative humidity decreases if the actual amount of moisture in the air remains constant. This is why, during hot days, especially in arid regions, we often experience very low relative humidity levels.

In the context of wildland fire behavior, this relationship is important because low humidity levels can significantly influence fire intensity and spread. Fires tend to burn more intensely and can spread more rapidly when conditions are dry and temperatures are high, which often corresponds with low relative humidity levels.

The other statements, while they may contain elements of truth, do not accurately reflect the general behavior of relative humidity in relation to temperature throughout the day or across different terrain. Understanding these dynamics is critical for predicting fire behavior and implementing effective fire management strategies.