Yellowstone's most famous geyser, Old Faithful, isn't as faithful as you would think, with eruption times varying by as much as 30 minutes. Plus or minus 10 minutes, what is the average time in between eruptions?

On average, you have to wait about an hour and a half in between the eruptions of this world-famous geyser. Intervals typically range from 79 to 109 minutes, and the eruptions can vary in terms of height too, usually anywhere from 100 to 180 feet.

Asked by Tom Cohen · Last updated 5 years ago · 1.6K views