What is the typical altitude range for high clouds?

• A. 20,000' to 60,000'
• B. Surface to 6,500'
• C. 6,500' to 20,000'
• D. 16,500' to 45,000'

Answer: (D)

High clouds form in the upper part of the troposphere, so their bases are well above the surface and their tops extend far upward. They’re typically ice clouds such as cirrus, cirrostratus, and cirrocumulus, usually starting near the lower end of the upper-troposphere range and reaching into the mid-upper levels. The range given—roughly 16,500 feet to 45,000 feet—best captures this broad span, including bases that can occur around the mid-teens to about 20,000 feet and tops reaching into the mid-40,000s feet. While some high clouds can rise higher than 45,000 feet, this interval aligns with common expectations for where high clouds are found. The other options place clouds in lower layers or mid-level ranges, which don’t fit high-cloud altitudes as well.