Which weather condition is considered hazardous for fire spread?

High temperatures are recognized as a hazardous condition for fire spread because they can significantly increase the likelihood of ignition and enhance the combustion process. In warm weather, materials such as vegetation and building materials reach their ignition temperature more quickly and can ignite more readily. High temperatures also lead to drier conditions, which can desiccate fuels, making them more susceptible to catching fire.

Additionally, high temperatures can exacerbate existing fire conditions, as they can contribute to the development of erratic fire behavior. The combination of increased heat and lower moisture levels can create an environment where fires spread rapidly and uncontrollably. This is particularly crucial for wildland fires, where temperatures directly influence fuel moisture levels and fire dynamics.

In contrast, high humidity generally slows the spread of fires as it increases the moisture content of fuels. Calm winds can limit the oxygen supply necessary for fire growth and spread, while light rain can help to dampen dry fuels and reduce fire intensity.