Wildland Firefighting Practice Exam

What are the two primary factors that influence fuel temperature?

1. Humidity and Soil Type

2. Air Temperature and Direct Sunlight

3. Wind Speed and Topography

4. Fuel Type and Moisture Content

The correct answer is: Air Temperature and Direct Sunlight

The two primary factors that influence fuel temperature are indeed air temperature and direct sunlight. Air temperature has a direct effect on the heat content of the environment, including the fuels present. Higher air temperatures can increase the temperature of the fuels, making them more susceptible to ignition. Direct sunlight is another crucial factor, as it can significantly raise the temperature of the fuels exposed to it. Sunlight directly heats the surface of the fuels, therefore increasing their temperature and possibly lowering their moisture content, which can also affect flammability. Humidity refers to the amount of moisture in the air, while soil type relates more to the ground's geological characteristics and water retention rather than the temperature of fuel. Wind speed can influence the rate at which fuel dries out or how quickly flames spread, and topography can affect how air moves through a landscape, but they do not fundamentally determine the temperature of the fuels themselves. Fuel type and moisture content are significant for understanding the behavior of fire, but they do not primarily control the temperature of the fuels as effectively as air temperature and sunlight do.