Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The start of September signals a gentle decrease in the average high-temperature, transitioning from a refreshing 19.8°C (67.6°F) in August to a mild 14.9°C (58.8°F). September nights in Harjavalta are marked by an average temperature drop to a frosty 9.7°C (49.5°F).Humidity
In September, the average relative humidity is 79%.Rainfall
In September, the rain falls for 15.9 days. Throughout September, 44mm (1.73") of precipitation is accumulated. Throughout the year, there are 154.3 rainfall days, and 508mm (20") of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Harjavalta, Finland, the average length of the day in September is 12h and 55min.On the first day of the month, sunrise is at 06:24 and sunset at 20:38. On the last day of September, in Harjavalta, Finland, sunrise is at 07:36 and sunset at 19:05 EEST.
Sunshine
In Harjavalta, the average sunshine in September is 7.4h.UV index
In September, the average daily maximum UV index in Harjavalta is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.Note: A maximum UV index of 3 in September translates into the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Frequently asked questions
What is the temperature in September in Harjavalta?
What is the average humidity in September in Harjavalta?
How many days does it rain in September in Harjavalta?
When it does not snow in Harjavalta?
Does it snow in Harjavalta in September?
What is the average length of the day in September in Harjavalta?
What time are sunrise and sunset in September in Harjavalta?
How long on average sun shines in September in Harjavalta?
What is the UV index reading in September in Harjavalta?
Average temperature in September
Harjavalta, Finland
- Average high temperature in September: 14.9°C
The warmest month (with the highest average high temperature) is July (20.7°C).
The month with the lowest average high temperature is January (-2.3°C).
- Average low temperature in September: 9.7°C
The month with the highest average low temperature is July (13.4°C).
The coldest month (with the lowest average low temperature) is January (-6°C).
Average pressure in September
Harjavalta, Finland
- Average pressure in September: 1012.6mbar
The month with the highest atmospheric pressure is May (1014.7mbar).
The month with the lowest atmospheric pressure is December (1006.8mbar).
Average wind speed in September
Harjavalta, Finland
- Average wind speed in September: 14.2km/h
The windiest month (with the highest average wind speed) is December (16.6km/h).
The calmest month (with the lowest average wind speed) is July (12.6km/h).
Average humidity in September
Harjavalta, Finland
- Average humidity in September: 79%
The month with the highest relative humidity is February (92%).
The month with the lowest relative humidity is May (69%).
Average rainfall in September
Harjavalta, Finland
- Average rainfall in September: 44mm
The wettest month (with the highest rainfall) is July (63mm).
The driest months (with the least rainfall) are March and April (31mm).
Average rainfall days in September
Harjavalta, Finland
- Average rainfall days in September: 15.9 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (5.8 days).
Average snowfall in September
Harjavalta, Finland
- Average snowfall in September: 0mm
The month with the highest snowfall is February (163mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Harjavalta, Finland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Harjavalta, Finland
- Average daylight in September: 12h and 5min
The month with the longest days is June (Average daylight: 19h and 12min).
The month with the shortest days is December (Average daylight: 5h and 36min).
- Average sunshine in September: 7h and 2min
The month with the most sunshine is June (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 2h and 0min).
Average sunshine days in September
Harjavalta, Finland
- Average sunshine days in September: 10.5 days
The month with the most sunshine days is May (14.2 days).
The month with the least sunshine days is November (8.5 days).
Average UV index in September
Harjavalta, Finland
- Average UV index in September: 3
The months with the highest UV index are June and 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
Harjavalta, Finland
- Average cloud cover in September: 47
The months with the most cloud cover are January, February and December (Cloud cover 71).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in September
Harjavalta, Finland
- Average visibility in September: 9km
The month with the highest visibility is June (10km).
The month with the lowest visibility is February (7km).
Harjavalta, Finland
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