In the wild, the snowy owl has an average lifespan of 10 years. The lifespan of the oldest known snowy owl in its natural habitat is 9 years and 5 months. In the wild, however, there are some snowy owls that are found to live for 15 to 20 years.
In captivity, these owls live longer and they tend to have a lifespan of more than 28 years. However, the maximum lifespan of the snowy owl ever recorded is 23 years and 10 months. It was a female snowy owl and she was banded in 1992 in Massachusetts.
Sources:
“Snowy Owl”. National Geographic
“Snowy Owl”. The Cornell Lab of Ornithology: All About Birds – Cornell University
“Snowy Owl”. Defenders of Wildlife
Holt, Denver W., Matt D. Larson, Norman Smith, Dave L. Evans and David F. Parmalee. 2015. Snowy Owl (Bubo scandiacus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.