Travel time: Year-round
Santorini, the jewel of the Cyclades, is defined by a distinct Mediterranean climate that is as dramatic as its volcanic landscape. While the island is synonymous with sunny summers, its weather is a complex interplay of strong Aegean winds, intense maritime light, and a surprising levels of humidity that sustain its ancient vineyards.
In Santorini, the day often begins with a heavy mist or "morning dew" that rolls in from the sea. Local farmers rely on this moisture to water the grapes, as the island has almost no natural spring water. By mid-morning, the Aegean sun burns through the haze, and the light becomes exceptionally sharp, reflecting off the white-washed buildings. As evening approaches, the temperature drops rapidly once the sun dips below the caldera, often accompanied by a freshening breeze that makes the night air feel much cooler than the daytime high suggests.
Summer is characterized by heat, cloudless skies, and the legendary Meltemi winds. These dry, northerly winds act as the island’s natural air conditioning, preventing temperatures from reaching the oppressive heights seen in mainland Greece. While highs usually hover around 29°C (84°F), the low humidity and constant breeze make it feel energetic rather than lethargic. However, the Meltemi can be powerful enough to disrupt ferry schedules and create heavy surf on the eastern beaches.
September is arguably the peak of thermal comfort. The sea, having baked all summer, reaches its warmest point (avg. 24°C/75°F), and the Meltemi winds begin to subside. By October, the air softens, and the first refreshing rains of the season may appear, turning the parched volcanic soil green almost overnight.
Winter is the season of storms and solitude. While mild (averaging 12°C–14°C / 54°F–57°F), the weather is defined by its unpredictability. One day might be clear and "spring-like," followed by a day of fierce "Ostria" (south) winds that bring moisture and occasionally Saharan dust. Locals adapt by retreating to cozy inland tavernas, far from the exposed caldera edges where the winds are most punishing.
Spring is a brief but vivid explosion of wildflowers across the terraces. Temperatures are pleasant for hiking (18°C–22°C / 64°F–72°F), but the seawater remains bracingly cold. This is when the island's unique light is at its most photogenic, as the air is remarkably clear before the summer haze develops.
The topography of the island creates notable weather differences:
Historically, Santorini was one of the most arid inhabited islands in the Aegean. Locals have adapted to this through unique architecture and agriculture. The cave houses (skafta) built into the volcanic ash are naturally thermoregulated, staying cool in summer and warm in winter. In the vineyards, you will notice vines woven into low, basket-like shapes called kouloura. This ingenious tradition protects the grapes from the relentless summer winds and traps the precious morning humidity within the basket, a direct response to the island's weather extremes.
Beyond the thermometer, Santorini weather is physical. It is the salt on your skin from the spray of the Aegean, the "push" of the wind as you walk the caldera path, and the sudden chill of the evening shadows. It is a climate of extremes held in balance—the intensity of the sun moderated by the tireless movement of the sea air.