Old Faithful can vary in height from 100-180 feet with an average near 130-140 feet. This has been the historical range of its recorded height. Eruptions normally last between 1.5 to 5 minutes.

Old Faithful is losing steam. Yellowstone National Park’s landmark geyser has spewed scalding-hot groundwater every 90 to 94 minutes on average, about 17 times a day, since time immemorial.

By the way, Old Faithful’s water can be as hot as 204 degrees F, which freezes faster than cold water in cold temperatures, according to Science Alert.

How Old Faithful works Old Faithful earned its name for its regular eruptions, which average every 92 minutes. Just after an eruption, there's a 15-minute recharge period with low water levels.