According to preliminary meteorological data based on climate reanalysis figures analyzed by the scientific team of meteo.gr / National Observatory of Athens (E.A.A.), the summer of 2025 ranked as the 3rd hottest in Greece since 1960.

The summer of 2025 saw temperatures above the seasonal norms nationwide. June was recorded as the hottest since 1960, while July was the 4th hottest. August was closer to average seasonal levels. Overall, of the 92 days of summer 2025, 70 days were somewhat or significantly above the 1991–2020 average for the same period.

Figure 1 shows the average temperature for the summer months (June, July, August) from 1960 to 2025 for all of Greece. Summer 2025 is recorded as the 3rd hottest, exceeding the 1991–2020 average by +1.5°C (black dashed line). It is very close to summer 2021 and just 0.3°C cooler than the 2nd hottest, 2012. The hottest summer remains last year, 2024, with a large margin over the second hottest.

The average summer temperature in Greece has increased by 2.4°C from 1960 to 2025.

Figure 2 shows the ranking of the summer in each region of Greece based on average summer temperatures from 1960 to 2025. In parts of Western Greece, the Peloponnese, and Eastern Macedonia, summer 2025 was the 2nd hottest since 1960, while in mainland areas it ranked 4th hottest. In Central Macedonia, the Attica region, and southern Peloponnese, it was the 3rd hottest. Cooler conditions were recorded in some areas of the Cyclades, parts of Western Macedonia, and Crete.