Density altitude is lower in which scenario?

• A. 15°C at 7,000 ft PA
• B. 4°C at 5,500 ft PA
• C. -9°C at 3,000 ft PA
• D. -18°C at 9,000 ft PA

Answer: (D)

Density altitude tells you how the air density compares to the standard atmosphere for a given altitude, and temperature relative to ISA is a big part of that adjustment. Colder air is denser than standard at the same pressure altitude, which lowers the density altitude; warmer air is less dense and raises it.

In these scenarios, the air is far colder than ISA in the high-altitude case (-18°C at 9,000 ft PA), producing the greatest densification relative to the standard model. That stronger cooling lowers the density altitude more than in the other cases, so the density altitude ends up the lowest among the options. The warmer or near-ISA cases yield higher density altitudes despite differences in height, so they don’t drop as low as the extreme cold scenario.