Which set of conditions results in a higher density altitude?

• A. Low Pressure, High Temperature, High Humidity
• B. High Pressure, Low Temperature, Low Humidity
• C. High Pressure, High Temperature, Low Humidity
• D. Low Pressure, Low Temperature, Low Humidity

Answer: (A)

Density altitude is the altitude in the standard atmosphere at which the air density would equal the density you’re experiencing. It increases when air density decreases. Air density drops with lower pressure, higher temperature, and higher humidity (moist air is lighter than dry air). So, the set with low pressure, high temperature, and high humidity gives the least dense air, making the density altitude the highest. The other options either have higher pressure, cooler temperatures, or drier air, which keep air density higher and thus result in a lower density altitude. In flight terms, higher density altitude means less air for lift and engine performance, so climb and power degrade.