By how much is the ramp temperature at an airport typically higher than the ambient air temperature?

The correct choice reflects a general understanding of temperature variations that can occur between the airport ramp and the surrounding ambient air. Ramp temperatures at an airport can often be substantially higher than the surrounding air temperature, primarily due to heat generated by aircraft engines, ramp operations, and the absorption of solar radiation by various surfaces like asphalt and concrete.

In many cases, during sunny or warm conditions, the heat absorbed by the ramp materials can elevate temperatures significantly, often leading to variations in the 25° to 45° range. This is especially common in busy airports where ground operations create additional warmth. The higher range also considers the cumulative effects of parked aircraft and equipment, which can contribute to an elevated microclimate around the ramp area.

Other options reflect lower temperature differentials that might not capture the potential extremes observed in operational settings at airports. In contrast, the 25° to 45° range encompasses a realistic assessment of these temperature differences, supporting the need for thorough consideration of heat conditions during ARFF operations.