Stratonimbus clouds are typically found at low altitudes, ranging from 2,000 to 8,000 feet (600 to 2,400 meters). However, they can occasionally extend higher, even reaching the middle level (up to 20,000 feet or 6,000 meters).

Here's a breakdown of their altitude range:

* Low level: 2,000 - 8,000 feet (600 - 2,400 meters)

* Middle level: Occasionally up to 20,000 feet (6,000 meters)

It's important to note that stratonimbus clouds are associated with persistent, widespread precipitation, often lasting for extended periods. They are also known for producing drizzle, snow, or even hail, depending on the temperature conditions.