September weather forecastAlonnisos, Greece

September

Weather in September

September, the first month of the autumn in Alonnisos, is also a moderately hot month, with an average temperature ranging between max 25°C (77°F) and min 16°C (60.8°F).

Temperature

September's arrival comes with a mild decrease in the average high-temperature, moving subtly from a moderately hot 28°C (82.4°F) in August to a still warm 25°C (77°F). Alonnisos anticipates an average minimum temperature of 16°C (60.8°F) in the month of September.

Rainfall

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

Sea temperature

In Alonnisos, the average seawater temperature in September is 23°C (73.4°F).
Note: Considering one's resistance to cold, elements like sunshine, wind, and the prevailing temperature matter when taking a swim in 23°C (73.4°F) waters. (For comparison, the Olympic swimming standard is set between 25°C (77°F) and 28°C (82.4°F).)

Daylight

The average length of the day in September 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, in Alonnisos, sunrise is at 07:20 and sunset at 19:08 EEST.

Sunshine

In September, the average sunshine is 10h.

UV index

In Alonnisos, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: A maximum high UV index of 6 in September translates into the following recommendations:
Sustain precautions and conform to sun safety norms. Preventing sunburn is necessary. Avoid exposure to the Sun and try to stay in the shade between 10 a.m. and 4 p.m., when UV radiation is most potent, but be aware that parasols or canopies may not offer full protection. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

Updated: Jul 23, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

During September, Alonnisos experiences an average high-temperature of 25°C (77°F) and a low-temperature of 16°C (60.8°F).

In Alonnisos, in September, it is raining for 3 days, with typically 46mm (1.81") of accumulated precipitation.

In Alonnisos, in September, the average water temperature is 23°C (73.4°F). A person's cold intolerance, with sunshine, wind, and air temperature, are essential factors for enjoying swimming in 23°C (73.4°F) water.

In Alonnisos, Greece, the average day length in September is 12h and 26min.

On the first day of September, sunrise is at 06:53 and sunset at 19:55. On the last day of the month, sunrise is at 07:20 and sunset at 19:08 EEST.

The average sunshine duration in September is 10h.

The average daily maximum UV index in September in Alonnisos is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

28°C

25°C

20°C

Average low temperature

Average rainfall

Average rainfall days

Average sea temperature

Average daylight

Average sunshine

Average UV index

Average temperature in September
Alonnisos, Greece

Average high temperature in September: 25°C

The warmest months (with the highest average high temperature) are July and August (28°C).
The month with the lowest average high temperature is January (10°C).

Average low temperature in September: 16°C

The months with the highest average low temperature are July and August (19°C).
The coldest month (with the lowest average low temperature) is January (4°C).

Average rainfall in September
Alonnisos, Greece

Average rainfall in September: 46mm

The wettest month (with the highest rainfall) is December (119mm).
The driest month (with the least rainfall) is July (22mm).

Average rainfall days in September
Alonnisos, Greece

Average rainfall days in September: 3 days

The month with the highest number of rainy days is December (10 days).
The months with the least rainy days are July, August and September (3 days).

Average sea temperature in September
Alonnisos, Greece

Average sea temperature in September: 23°C

The best months for swimming (with the highest average sea temperature) are July and August (24°C).
The coldest months (with the lowest average sea temperature) are January, February and March (14°C).

Average daylight in September /
Average sunshine in September
Alonnisos, Greece

Average daylight in September: 12h and 24min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

Average sunshine in September: 10h

The month with the most sunshine is July (Average sunshine: 13h).
The months with the least sunshine are January and December (Average sunshine: 4h).

Average UV index in September
Alonnisos, Greece

Average UV index in September: 6

The months with the highest UV index are June and July (UV index 9).
The months with the lowest UV index are January, November and December (UV index 2).