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FinlandThe weather in September in Helsinki
It's cool to moderate in September in Helsinki with an average temperature of 16°C. Temperatures this month range from a low of 13°C to a high of 18°C. At night, you can expect temperatures between 8°C and 13°C.
Looking for sun and warm weather? September isn’t a good month to be in Helsinki. The temperatures are too low for a warm stay this month.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Helsinki, Finland. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 23°C in 2018, Helsinki reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 5°C in 2014. The extreme nighttime temperatures ranged from a lowest recorded value of -2°C to a highest value of 18°C.
Rainfall amount
In September, there is an average of 51 mm of precipitation, spread over 9 days. The wind speed is around 4 Bft, mostly coming from the South.
Daily weather in September for Helsinki
Click on any day in September to get detailed info about the usual weather on that day in Helsinki. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Helsinki | New York | |
|---|---|---|
| Average temperature | 16°C | 27°C |
| Max. temperature | 18°C | 31°C |
| Min. temperature | 8°C | -5°C |
| Total precipitation | 51 mm | 57 mm |
| Rainy days | 9 days | 9 days |
Start of September
The month of September starts in Helsinki with mild temps, averaging around 18°C during the day and nights around 11°C.
Mid September
By mid-September, daytime temps drop to around 16°C, with nights around 10°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Helsinki is around 14°C, while nighttime temps are about 9°C. A shower might pop up, but overall, the weather will be dry and sunny.
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UV index
The UV index is a maximum of 4 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Check out the climate of Helsinki for all months and discover the best travel time
Curious about the weather in other parts of Finland? Check out the climate and weather for spots like Rovaniemi, Kuusamo, Tampere, or explore other destinations in Finland.
Temperature charts
These charts show the average temperatures in September in Helsinki, Finland. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Helsinki
Temperature in September in Helsinki over the years
Precipitation charts
These charts show the average amount of precipitation in September in Helsinki, Finland. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Helsinki
Total precipitation in September in Helsinki over the years
Daily UV index in September in Helsinki
This chart shows the average daily UV index in September in Helsinki, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Helsinki
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Average weather in Helsinki by month
Click on a month below to see detailed weather info for Helsinki. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.