As altitude increases, what happens to air temperature and density?

As altitude increases, what happens to air temperature and density?

• A. Increases
• B. Stays the same
• C. Fluctuates
• D. Decreases

Answer: (D)

As you gain altitude, the air becomes thinner overall, and in the lower atmosphere it also tends to get cooler. The key driver is that air pressure drops quickly with height, so the air expands and there are fewer molecules in a given volume. While temperature can influence density, the rapid fall in pressure with height means density falls overall. This thinner air means less lift for a drone and reduced engine/propeller efficiency, which is why higher altitudes are more challenging to fly in. In the typical flight region, both temperature and density decrease as altitude increases, so the best answer reflects decreasing air density (and the accompanying cooler temperatures in the lower atmosphere).

As you gain altitude, the air becomes thinner overall, and in the lower atmosphere it also tends to get cooler. The key driver is that air pressure drops quickly with height, so the air expands and there are fewer molecules in a given volume. While temperature can influence density, the rapid fall in pressure with height means density falls overall. This thinner air means less lift for a drone and reduced engine/propeller efficiency, which is why higher altitudes are more challenging to fly in. In the typical flight region, both temperature and density decrease as altitude increases, so the best answer reflects decreasing air density (and the accompanying cooler temperatures in the lower atmosphere).