How high in the atmosphere is an average lightning cloud?

Question

1 mile? More?

Answer 1

You would have more success with this question in the "Weather" section of Yahoo Answers.  But nevertheless, I will attempt an answer (keep in mind this answer is coming from a geologist, not a meteorologist!).  There is no such thing as an "average lightening cloud".  Lightening is the product of friction between air molecules, and is a very complex process that is still not fully understood.  You could say that a cumulonimbus thunder cloud is an "average" producer of lightening, since most of the lightening observable from the ground comes from such clouds.  The lightening produced by these types of clouds can be as high as 40,000 ft. above sea level, and very often at 0 ft. above sea level (that's when the lightening is discharging from the cloud into the earth) and literally everything in between.  The bottom of such a storm cloud is usually at several thousand feet above the ground, but that height is a function of many variables such as temperature, pressure, wind direction, etc.

Answer 2

It will be at less than 30,000 feet. Because I have never heard that the lightening struck the flights when it is flying.Normally the flights are maintaining the average height of 30,000 feet.