September weather forecastTrosa, Sweden

September

Weather in September

The first month of the autumn, September, is also an enjoyable month in Trosa, Sweden, with temperature in the range of an average high of 16.5°C (61.7°F) and an average low of 9.3°C (48.7°F).

Temperature

As August makes way for September, Trosa's average high-temperature eases from an agreeable 21.1°C (70°F) to a refreshing 16.5°C (61.7°F). The nighttime temperature dips to a frosty 9.3°C (48.7°F) on average during September.

Humidity

The average relative humidity in September is 79%.

Rainfall

In Trosa, in September, during 12.5 rainfall days, 28mm (1.1") of precipitation is typically accumulated. In Trosa, during the entire year, the rain falls for 143.7 days and collects up to 387mm (15.24") of precipitation.

Snowfall

In Trosa, Sweden, snow does not fall in June through September.

Sea temperature

In September, the average sea temperature is 14.8°C (58.6°F).
Note: You can swim in 14.8°C (58.6°F) below 10°C (50°F) with proper thermal wear; failing that, the cold shock and respiratory challenges are nearly certain. A short span at 13°C (55.4°F) without it is tough.

Daylight

The average length of the day in September is 12h and 50min.
On the first day of the month, sunrise is at 05:48 and sunset at 19:50. On the last day of September, sunrise is at 06:53 and sunset at 18:25 CEST.

Sunshine

In Trosa, Sweden, the average sunshine in September is 8.1h.

UV index

The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: A maximum high UV index of 3 in September translates into the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.

Frequently asked questions

The high-temperature during September is 16.5°C (61.7°F) and the low-temperature is 9.3°C (48.7°F).

The average relative humidity in September is 79%.

In Trosa, in September, during 12.5 rainfall days, 28mm (1.1") of precipitation is typically accumulated.

In Trosa, snow does not fall in June through September.

In Trosa, in September, it doesn't snow. In October, it regularly snows.

In September, the average sea temperature is 14.8°C (58.6°F). Swimming in 14.8°C (58.6°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

In September, the average day length is 12h and 50min.

In September, on the first day of the month, sunrise is at 05:48 and sunset at 19:50. On the last day of the month, sunrise is at 06:53 and sunset at 18:25 CEST.

The average sunshine duration in September is 8.1h.

In September, the average daily maximum UV index in Trosa is 3. A UV Index estimate of 3 to 5 represents a medium hazard to health from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sea temperature
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Trosa, Sweden

  • Average high temperature in September: 16.5°C

The warmest month (with the highest average high temperature) is July (22.1°C).
The month with the lowest average high temperature is January (-0.6°C).

  • Average low temperature in September: 9.3°C

The month with the highest average low temperature is July (12.8°C).
The coldest month (with the lowest average low temperature) is January (-3.9°C).

Average pressure in September
Trosa, Sweden

  • Average pressure in September: 1013.5mbar

The month with the highest atmospheric pressure is May (1014.8mbar).
The month with the lowest atmospheric pressure is December (1008.1mbar).

Average wind speed in September
Trosa, Sweden

  • Average wind speed in September: 12.9km/h

The windiest month (with the highest average wind speed) is December (16km/h).
The calmest month (with the lowest average wind speed) is August (11.5km/h).

Average humidity in September
Trosa, Sweden

  • Average humidity in September: 79%

The months with the highest relative humidity are January, February, November and December (89%).
The month with the lowest relative humidity is May (70%).

Average rainfall in September
Trosa, Sweden

  • Average rainfall in September: 28mm

The wettest month (with the highest rainfall) is October (41mm).
The driest month (with the least rainfall) is April (18mm).

Average rainfall days in September
Trosa, Sweden

  • Average rainfall days in September: 12.5 days

The months with the highest number of rainy days are July and August (14.6 days).
The month with the least rainy days is February (7.1 days).

Average snowfall in September
Trosa, Sweden

  • Average snowfall in September: 0mm

The month with the highest snowfall is January (110mm).
The months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in September
Trosa, Sweden

  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (14 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in September
Trosa, Sweden

  • Average sea temperature in September: 14.8°C

The best month for swimming (with the highest average sea temperature) is August (18.7°C).
The coldest month (with the lowest average sea temperature) is February (1°C).

Average daylight in September /
Average sunshine in September
Trosa, Sweden

  • Average daylight in September: 12h and 48min

The month with the longest days is June (Average daylight: 18h and 18min).
The month with the shortest days is December (Average daylight: 6h and 24min).

  • Average sunshine in September: 8h and 6min

The month with the most sunshine is June (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 2h and 30min).

Average sunshine days in September
Trosa, Sweden

  • Average sunshine days in September: 14.5 days

The month with the most sunshine days is April (14.6 days).
The month with the least sunshine days is February (10.3 days).

Average UV index in September
Trosa, Sweden

  • Average UV index in September: 3

The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Trosa, Sweden

  • Average cloud cover in September: 44

The months with the most cloud cover are February and December (Cloud cover 67).
The months with the least cloud cover are June, July and August (Cloud cover 40).

Average visibility in September
Trosa, Sweden

  • Average visibility in September: 9km

The months with the highest visibility are April, May, June, July, August, September and October (9km).
The months with the lowest visibility are January, February, March, November and December (8km).