Greece recorded the largest seasonal variation in air traffic among the zones covered by EUROCONTROL’s 2025 analysis, with a Seasonality Index of 88. North Macedonia, Albania and Croatia followed, while Finland had the most even profile, at 13. The index measures the gap between each zone’s busiest and quietest months; it does not compare total traffic volumes. The analysis includes all flights, including overflights.
The index is calculated from monthly daily-average flight totals, each compared with the zone’s annual daily average. Greece’s August peak reached 147 on that scale, against 59 in January. North Macedonia scored 83, Albania 79 and Croatia 74. EUROCONTROL linked the sharp summer surges in Balkan and Mediterranean markets to leisure traffic concentrated in July and August.
Finland’s smaller seasonal swing reflects winter traffic, particularly to northern Finland and Lapland. The Canary Islands and Morocco also had relatively balanced profiles, with indices of 19 and 17 respectively, associated with year-round leisure demand. Among German-speaking zones, Austria scored 52, Switzerland 42 and Germany 37.
The results cover traffic zones in 2025, not airport arrivals and departures alone, and include non-European areas such as Morocco and the Canary Islands. Ukraine, Moldova and Israel were excluded. EUROCONTROL noted that the method can also be applied separately to arrivals and departures or to overflights, and extended across multiple years; the single-year comparison does not establish whether the same patterns persist in other years.