September weather forecast
Turku, Finland

September marks Autumn's arrival in Turku, exhibiting a more noticeable drop in temperature compared to August. In accordance with it, daylight hours diminish as well, but still allow for substantially bright days. Though cool, the sea remains suitable for a quick swim, at least at the start of the month. The rainfall steadily increases and the air turns crisper, hinting at a colder season on the way. All said, September still showcases vibrant fall colours and offers delightful weather conditions for tourist activities.

Temperature

With the beginning of September, the average high-temperature shows a decrease, transitioning from an agreeable 20.5°C (68.9°F) in August to a moderate 14.9°C (58.8°F). Turku's temperature drops to an average low of 7.2°C (45°F) during the nights of September.

Rainfall

In Turku, in September, during 9 rainfall days, 64mm (2.52") of precipitation is typically accumulated. In Turku, during the entire year, the rain falls for 116 days and collects up to 723mm (28.46") of precipitation.

Sea temperature

In Turku, in September, the average water temperature is 10.3°C (50.5°F).
Note: Swimming in 10.3°C (50.5°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

In September, the average length of the day is 12h and 53min.
On the first day of September, sunrise is at 06:26 and sunset at 20:35. On the last day of the month, sunrise is at 07:35 and sunset at 19:05 EEST.

Sunshine

In September, the average sunshine in Turku is 5.2h.

UV index

In Turku, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.
Note: A daily maximum UV index of 3 in September translates into the following instructions:
Exercise prevention - Warding off sunburn is urged. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Tightly woven clothing, when worn loosely, shields effectively against the Sun.