September weather forecast
Alonnisos, Greece

September, the first month of the autumn in Alonnisos, is still a warm month, with an average temperature fluctuating between 16°C (60.8°F) and 25°C (77°F).

Temperature

Alonnisos's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's 28°C (82.4°F) to a still moderately hot 25°C (77°F). During September, Alonnisos records an average temperature of 16°C (60.8°F) at night.

Rainfall

In September, the rain falls for 3 days. Throughout September, 46mm (1.81") of precipitation is accumulated. In Alonnisos, during the entire year, the rain falls for 79 days and collects up to 725mm (28.54") of precipitation.

Sea temperature

In Alonnisos, in September, the average water temperature is 23°C (73.4°F).
Note: When considering a person's aversion to cold, factors like sunshine, wind, and atmospheric temperature are key. Swimming in 23°C (73.4°F) might be delightful. (Remember: The Olympics' swimming events have water temperatures between 25°C (77°F) and 28°C (82.4°F).)

Daylight

The average length of the day in September in Alonnisos is 12h and 26min.
On the first day of the month, sunrise is at 06:53 and sunset at 19:55. On the last day of September, sunrise is at 07:20 and sunset at 19:08 EEST.

Sunshine

The average sunshine in September in Alonnisos is 10h.

UV index

In Alonnisos, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In September, an average UV index of 6 transforms into the following instructions:
Inhibit overexposure. Warding off sun damage is of utmost importance. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Heads up! Sand and water reflection magnifies the UV exposure from the Sun.