Interanuais

Interanuais is a term used to describe phenomena, data or comparisons that occur across two or more calendar years. Derived from inter- (between) and anual (yearly), it is commonly employed in Portuguese-language contexts across fields such as statistics, economics, climatology and demography to emphasize changes or patterns from one year to the next.

In statistics and econometrics, the expression variação interanual or crescimento interanual refers to the change in a metric compared with the same period in the previous year. This approach highlights year-to-year dynamics and helps control for within-year seasonal effects. In climate science, variabilidade interanual denotes fluctuations in climate variables—such as rainfall or temperature—from year to year, often driven by large-scale climate modes like El Niño and La Niña. In demography and environmental studies, interanuais describe trends or comparisons that span consecutive years, such as birth rates, mortality or migration figures.

Interanuais are distinct from intraannual or intrayear analyses, which focus on variability within a single year, and from seasonal analyses that track regular, repeating patterns within each year. They sit alongside other time-scale concepts such as interdecadal or triannual analyses, which reference longer or differently spaced intervals.

Measurement and data considerations for interanuais include choosing appropriate base years, aligning calendar definitions (for example, leap years), and handling data revisions. Analysts should be aware of outliers and the influence of unusual events in a given year, which can disproportionately affect interannual comparisons.

See also: year-over-year, interannual variability, time series analysis, seasonality.