What impact does relative humidity have on wildfire behavior?

Relative humidity plays a significant role in wildfire behavior, particularly in how it influences the moisture content of fuels and the overall fire environment. When humidity levels are higher, excess moisture in the air can slow down the combustion process. This occurs because well-hydrated fuels are less likely to ignite easily and burn quickly. Higher humidity levels contribute to the dampening of fine fuels—like grasses and leaves—which can ultimately reduce fire spread and intensity.

In contrast, lower humidity levels often lead to drier conditions, which can increase the likelihood of wildfire ignition and rapid spreading. Therefore, understanding the relationship between relative humidity and fire activity is crucial for wildfire mitigation and management strategies. Higher humidity directly correlates with dampened fire behavior, allowing for safer conditions in fire-prone areas.