Occurring between years, or from one year to the next(adjective)
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Use "interannual" in a sentence
"An analysis of the variation of large-scale drought with SSTs revealed connections at interannual and possibly decadal time scales."
"… Summary: The Southern Oscillation and increasing GHGs continue to be, respectively, the dominant factors affecting interannual and decadal temperature change."
"His statement about the lack of an adequate observational network to diagnose the climate's response to interannual variability was decontextualized and thus trumped up as has been done in the past to make it appear it's an admission that global warming has ceased."