Seasonal variations are recurring data shifts observed at fixed intervals like months, quarters, or seasons.
These shifts are driven by environmental, social, and cultural influences such as climate, festivals, holidays, and weather.
For instance, ice cream sales typically rise in summer and fall in winter, or tourism surges during holidays.
These patterns recur annually and are predictable.
They are distinct from long-term secular trends, economic cycles (cyclic variations), or unforeseen events (irregular variations).
Consequently, variations attributable to climate and festivals are correctly categorized as seasonal variations.