Galissas Temperature by Month

The average annual maximum temperature in Galissas, Cyclades, Greece is 20°C (68°F), with daytime highs ranging from 15°C (59°F) in January to 27°C (81°F) in August. This page covers monthly averages, day-night differences, and how Galissas compares to cities worldwide.

Visitors to Galissas can expect significant temperature changes throughout the year. Nighttime temperatures also vary widely, ranging from 24°C (75°F) in August to 12°C (54°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Galissas by month:

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating.

The chart below shows the average temperature throughout the year:

Galissas's average annual maximum temperature is 20°C (68°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Queenstown, New Zealand averages 10°C (50°F) annually, remember seasons are flipped, so its coldest months fall in June and July.

New York City, USA averages 17°C (63°F) a year, with hot humid summers and cold winters that bring regular snowfall.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Galissas, January is the coolest month, with average highs of 15°C (59°F) and humidity around 72%, considered high. In August, the warmest month, temperatures average 27°C (81°F) with 70% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Galissas's weather, including monthly rainfall, sunshine hours, and humidity, visit our Galissas climate page.