September weather forecastSønderborg, Denmark

September

Weather in September

With autumn setting in, September sees a significant drop in average temperatures in Sønderborg. The weather during this month marks a change from the warm days of August, paving the way for cooler conditions. A gradual decrease in daylight hours coupled with the declining sea temperature signals the impending approach of winters. Despite the slightly cooler air, September's weather continues to provide comfortable conditions for exploring the city's local attractions. The harmonious transition from summer to autumn brings in a spectacular riot of fall colors in Sønderborg.

Temperature

During the shift to September, a minor reduction in average high-temperature is observed, shifting from an agreeable 20.3°C (68.5°F) in August to an enjoyable 17°C (62.6°F). September records a small disparity from daytime temperatures, marking an average low-temperature of 12.7°C (54.9°F).

Humidity

The average relative humidity in September is 80%.

Rainfall

In Sønderborg, in September, during 14.2 rainfall days, 24mm (0.94") of precipitation is typically accumulated. Throughout the year, there are 153.2 rainfall days, and 268mm (10.55") of precipitation is accumulated.

Snowfall

May through October are months without snowfall in Sønderborg.

Sea temperature

In Sønderborg, the average seawater temperature in September is 15°C (59°F).
Note: In 15°C (59°F), swimming is not an enjoyable activity for most. The challenge of managing one's breathing increases as the temperature goes under 21°C (69.8°F).

Daylight

The average length of the day in September is 12h and 43min.
On the first day of September, sunrise is at 06:28 and sunset at 20:12. On the last day of the month, sunrise is at 07:22 and sunset at 18:58 CEST.

Sunshine

In September, the average sunshine is 7.3h.

UV index

In September, the average daily maximum UV index in Sønderborg, Denmark, is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: A maximum high UV index of 4 in September translates into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. To guard against the harmful effects of the Sun, minimize exposure during midday. Opt for tightly woven and loose clothing to enhance protection from the Sun.

Updated: Jul 17, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

An average high-temperature, in September, in Sønderborg, is 17°C (62.6°F) and the average low-temperature is 12.7°C (54.9°F).

The average relative humidity in September is 80%.

In Sønderborg, in September, during 14.2 rainfall days, 24mm (0.94") of precipitation is typically accumulated.

May through October are months without snowfall.

In Sønderborg, the average seawater temperature in September is 15°C (59°F). For most, swimming in 15°C (59°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).

In Sønderborg, the average day length in September is 12h and 43min.

In September, on the first day of the month, sunrise is at 06:28 and sunset at 20:12. On the last day of the month, sunrise is at 07:22 and sunset at 18:58 CEST.

In Sønderborg, the average sunshine duration in September is 7.3h.

In Sønderborg, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health risk from unsafe exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

20.3°C

17°C

12.7°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

17.4km/h

18.8km/h

21.4km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

12.3

12.4

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Sønderborg, Denmark

Average high temperature in September: 17°C

The warmest month (with the highest average high temperature) is August (20.3°C).
The month with the lowest average high temperature is January (3.3°C).

Average low temperature in September: 12.7°C

The month with the highest average low temperature is August (15°C).
The coldest month (with the lowest average low temperature) is February (0.5°C).

Average pressure in September
Sønderborg, Denmark

Average pressure in September: 1015.4mbar

The months with the highest atmospheric pressure are April and May (1015.7mbar).
The month with the lowest atmospheric pressure is November (1010.9mbar).

Average wind speed in September
Sønderborg, Denmark

Average wind speed in September: 18.2km/h

The windiest month (with the highest average wind speed) is December (22.5km/h).
The calmest month (with the lowest average wind speed) is July (16.2km/h).

Average humidity in September
Sønderborg, Denmark

Average humidity in September: 80%

The months with the highest relative humidity are January and December (87%).
The months with the lowest relative humidity are April, May and August (77%).

Average rainfall in September
Sønderborg, Denmark

Average rainfall in September: 24mm

The wettest month (with the highest rainfall) is July (32mm).
The driest month (with the least rainfall) is April (12mm).

Average rainfall days in September
Sønderborg, Denmark

Average rainfall days in September: 14.2 days

The month with the highest number of rainy days is July (16.4 days).
The month with the least rainy days is February (9.4 days).

Average snowfall in September
Sønderborg, Denmark

Average snowfall in September: 0mm

The month with the highest snowfall is February (18mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).

Average snowfall days in September
Sønderborg, Denmark

Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (6.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in September
Sønderborg, Denmark

Average sea temperature in September: 15°C

The best month for swimming (with the highest average sea temperature) is August (18°C).
The coldest month (with the lowest average sea temperature) is February (1°C).

Average daylight in September /
Average sunshine in September
Sønderborg, Denmark

Average daylight in September: 12h and 42min

The month with the longest days is June (Average daylight: 17h and 18min).
The month with the shortest days is December (Average daylight: 7h and 18min).

Average sunshine in September: 7h and 18min

The month with the most sunshine is June (Average sunshine: 9h and 30min).
The month with the least sunshine is February (Average sunshine: 3h and 6min).

Average sunshine days in September
Sønderborg, Denmark

Average sunshine days in September: 11 days

The month with the most sunshine days is April (17.1 days).
The month with the least sunshine days is December (9.9 days).

Average UV index in September
Sønderborg, Denmark

Average UV index in September: 4

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

Average cloud cover in September
Sønderborg, Denmark

Average cloud cover in September: 49

The months with the most cloud cover are February and December (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 41).

Average visibility in September
Sønderborg, Denmark

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).