interannual

adjective

in·​ter·​an·​nu·​al ˌin-tər-ˈan-yə(-wə)l 

-yü-əl

variants or less commonly inter-annual

: occurring between, relating to, or involving two or more years : occurring or observed in different years

interannual changes in weather patterns

Word History

First Known Use

1881, in the meaning defined above