September weather forecastHoutskär, Finland
September
Weather in September
The first month of the autumn, September, is still a mild month in Houtskär, Finland, with an average temperature fluctuating between 13.2°C (55.8°F) and 14.9°C (58.8°F).Temperature
September's arrival aligns with a minor decrease in average high-temperatures, from August's enjoyable 18.1°C (64.6°F) to a moderate 14.9°C (58.8°F). During the September nights, Houtskär's temperature maintains an average close to the daytime highs, settling at a still mild 13.2°C (55.8°F).Humidity
The months with the lowest humidity are August through October, with an average relative humidity of 78%.Rainfall
September is the month with the most rainfall in Houtskär. Rain falls for 14.2 days and accumulates 38mm (1.5") of precipitation.Snowfall
In Houtskär, snow does not fall in June through September.Sea temperature
In Houtskär, the average seawater temperature in September is 9.7°C (49.5°F).Note: It is life-risking to swim in 9.7°C (49.5°F). Briefly staying in 13°C (55.4°F) waters feels unsettling, and temperatures below 10°C (50°F) might result in cold shock and loss of breath control, hinging on personal endurance.
Daylight
In September, the average length of the day is 12h and 52min.On the first day of September, sunrise is at 06:30 and sunset at 20:38. On the last day of the month, sunrise is at 07:39 and sunset at 19:09 EEST.
Sunshine
In Houtskär, the average sunshine in September is 8.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.Note: The daily high UV index of 4 in September translates into this advice:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Houtskär, Finland
- Average high temperature in September: 14.9°C
The warmest month (with the highest average high temperature) is August (18.1°C).
The month with the lowest average high temperature is February (0.3°C).
- Average low temperature in September: 13.2°C
The month with the highest average low temperature is August (16.3°C).
The coldest month (with the lowest average low temperature) is February (-1.7°C).
Average pressure in September
Houtskär, Finland
- Average pressure in September: 1013.3mbar
The month with the highest atmospheric pressure is May (1015mbar).
The month with the lowest atmospheric pressure is December (1007.8mbar).
Average wind speed in September
Houtskär, Finland
- Average wind speed in September: 26.4km/h
The windiest month (with the highest average wind speed) is December (34.1km/h).
The calmest month (with the lowest average wind speed) is July (21.2km/h).
Average humidity in September
Houtskär, Finland
- Average humidity in September: 78%
The months with the highest relative humidity are February and March (84%).
The months with the lowest relative humidity are August, September and October (78%).
Average rainfall in September
Houtskär, Finland
- Average rainfall in September: 38mm
The wettest month (with the highest rainfall) is September (38mm).
The driest month (with the least rainfall) is April (12mm).
Average rainfall days in September
Houtskär, Finland
- Average rainfall days in September: 14.2 days
The month with the highest number of rainy days is August (14.8 days).
The month with the least rainy days is February (5.8 days).
Average snowfall in September
Houtskär, Finland
- Average snowfall in September: 0mm
The month with the highest snowfall is January (41mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Houtskär, Finland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Houtskär, Finland
- Average sea temperature in September: 9.7°C
The best month for swimming (with the highest average sea temperature) is August (12.3°C).
The coldest month (with the lowest average sea temperature) is March (-0.2°C).
Average daylight in September /
Average sunshine in September
Houtskär, Finland
- Average daylight in September: 12h and 54min
The month with the longest days is June (Average daylight: 18h and 48min).
The month with the shortest days is December (Average daylight: 6h and 0min).
- Average sunshine in September: 8h and 6min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 2h and 0min).
Average sunshine days in September
Houtskär, Finland
- Average sunshine days in September: 12.9 days
The month with the most sunshine days is May (19.3 days).
The month with the least sunshine days is December (8.9 days).
Average UV index in September
Houtskär, Finland
- Average UV index in September: 4
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March and December (UV index 1).
Average cloud cover in September
Houtskär, Finland
- Average cloud cover in September: 41
The months with the most cloud cover are January and December (Cloud cover 71).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Houtskär, Finland
- Average visibility in September: 10km
The months with the highest visibility are April, May, June, July, August, September and October (10km).
The months with the lowest visibility are January, February, March, November and December (9km).
