Which altitude has a standard temperature of -7 degrees Celsius?

• A. 11,000 ft
• B. 2,000 ft
• C. 6,000 ft
• D. 8,500 ft

Answer: (A)

In the International Standard Atmosphere, temperature decreases by about 2°C for every 1,000 feet you climb, starting from a sea-level temperature of 15°C. To find where the temperature reaches -7°C, calculate the drop from sea level: 11,000 feet × 2°C per 1,000 ft equals a 22°C drop. So 15°C minus 22°C equals -7°C. That means the standard temperature of -7°C occurs at 11,000 feet.

For quick context, at 2,000 ft the temperature is about 11°C, at 6,000 ft about 3°C, and at 8,500 ft about -2°C, which confirms that 11,000 ft is the correct altitude for -7°C.