syyskuu
Syyskuu is the Finnish word for the month of September. It is the ninth month of the Gregorian calendar. Syyskuu marks the transition from summer to autumn in Finland, characterized by changing foliage, cooler temperatures, and shorter daylight hours. The average temperature in Helsinki during September ranges from 8 to 13 degrees Celsius (46 to 55 degrees Fahrenheit). Nights begin to feel noticeably colder, and frost can occur in some parts of the country towards the end of the month.
The autumnal equinox, when day and night are of approximately equal length, typically falls in late September,