Trondheim
Norway
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Trondheim, Norway

The first month of the autumn, September, is still a cool month in Trondheim, Norway, with average temperature varying between 12°C (53.6°F) and 6°C (42.8°F).

Temperature

In Trondheim, the average high-temperature drops, from a comfortable 17°C (62.6°F) in August, to a fresh 12°C (53.6°F). The average low-temperature, in Trondheim, Norway, is 6°C (42.8°F).

Rainfall

September is the month with the most rainfall. Rain falls for 24 days and accumulates 133mm (5.2") of precipitation.

Sea temperature

In September, the average sea temperature in Trondheim is 13.4°C (56.1°F).
Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C (55.4°F) is not comfortable.

Daylight

In Trondheim, Norway, the average length of the day is 13h.

Sunshine

In Trondheim, the average sunshine is 3h.

UV index

In September, the average daily maximum UV index in Trondheim is 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to the UV radiation for the average person.
Note: The daily maximum UV index of 2 interpret into the following advice:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Trondheim?

The average high-temperature, in September, in Trondheim, Norway, is 12°C (53.6°F), while the average low-temperature is 6°C (42.8°F).

How many days does it rain in September in Trondheim?

In September, in Trondheim, Norway, the rain falls for 24 days. Throughout September, 133mm (5.2") of precipitation is accumulated.

What is the rainiest month in Trondheim?

September is the month with the most rainfall. Rain falls for 24 days and accumulates 133mm (5.2") of precipitation.

What is the sea water temperature in September in Trondheim?

In Trondheim, the average seawater temperature in September is 13.4°C (56.1°F). Swimming in 13.4°C (56.1°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the average length of the day in September in Trondheim?

In September, the average length of the day in Trondheim is 13h.

How long on average sun shines in September in Trondheim?

In Trondheim, Norway, the average sunshine in September is 3h.

How high is the UV index in September in Trondheim?

In Trondheim, Norway, the average daily maximum UV index in September is 2. A UV Index reading of 2, and below, represents a minimal hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Trondheim, Norway
  • Average high temperature in September: 12°C

The warmest month (with the highest average high temperature) is August (17°C).
Months with the lowest average high temperature are January and February (0°C).

  • Average low temperature in September: 6°C

Months with the highest average low temperature are July and August (9°C).
Coldest months (with the lowest average low temperature) are January and February (-5°C).

Average rainfall in September - Trondheim, Norway
  • Average rainfall in September: 133mm

The wettest month (with the highest rainfall) is September (133mm).
The driest month (with the lowest rainfall) is May (53mm).

Average rainfall days in September - Trondheim, Norway
  • Average rainfall days in September: 24 days

Months with the highest number of rainy days are September and December (24 days).
The month with the lowest number of rainy days is May (15 days).

Average sea temperature in September - Trondheim, Norway
  • Average sea temperature in September: 13.4°C

The best month for swimming (with the highest average sea temperature) is August (14.8°C).
The coldest month (with the lowest average sea temperature) is March (4.9°C).

Average daylight in September / Average sunshine in September - Trondheim, Norway
  • Average daylight in September: 13h

The month with the longest days is June (Average daylight: 20.4h).
The month with shortest days is December (Average daylight: 4.7h).

  • Average sunshine in September: 3h

Months with most sunshine are May and June (Average sunshine: 7h).
Months with least sunshine are January and December (Average sunshine: 0).

Average UV index in September - Trondheim, Norway
  • Average UV index in September: 2

Months with the highest UV index are June and July (UV index 4).
Months with the lowest UV index are January, February, November and December (UV index 0).