How Do You Track Altitude of Cloud Bases?

There’s a simple math formula for pilots to estimate that height in poor weather.

Meg Godlewski

Wednesday, February 25, 2026 at 09:00 AM ET

Verified

Edited By:

Travis Tingle

There’s a basic calculation pilots can use to avoid cloud bases. [Credit: FLYING Archive]

Key Takeaways:

Student pilots can estimate cloud base above ground level (AGL) when automated weather is unreliable, especially important for determining if there's enough room for a traffic pattern.
The calculation involves subtracting the dew point (Fahrenheit) from the surface temperature (Fahrenheit), dividing the result by 4.4, and then multiplying by 1,000 to get the cloud base in feet AGL.
For example, if the temperature is 42°F and the dew point is 20°F, the cloud base would be estimated at 5,000 feet AGL.
Pilots should remain vigilant as clouds can drop and fog can form quickly, particularly when the temperature-dew point spread converges later in the day.

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Question: I am a student pilot and have learned that the airport’s automated weather machine is prone to malfunctioning and unreliable, so we’ve been taught not to trust it. The winter is all low clouds, and sometimes the pattern is a little iffy. Is there an easy way to determine the base of the clouds beyond taking off and seeing if you have the room to fly the pattern?