Oslo Weather in September

Oslo in September sees moderate temperatures, with highs around 16°C (61°F) and overnight lows of 7°C (45°F). Rainfall is fairly high at around 89 mm (3.5 in) on average, so pack waterproofs just in case.

Rainfall in Oslo in September

Typically, about 16 days will experience rainfall, with an average of 89 mm (3.5 in) for the month. Expect a fairly normal spread of rainfall this month, with no particular pattern of very heavy or very persistent showers.

Temperature in Oslo in September

In September, Oslo gets moderate temperatures, with highs of 16°C (61°F). Nights cool to around 7°C (45°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. Nights drop to 7°C (45°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.

Sunshine in Oslo in September

The month experiences a moderate amount of sunlight, with 146 hours of sunshine. This provides a nice balance between sunshine and clouds.

Wind Speed in Oslo in September

Average wind conditions reach 2 m/s (4 knots) in September. This creates comfortable weather with light winds that gently move vegetation. Keep in mind this is an average. Daily conditions range from near-calm to more noticeable wind.

Average water temperature in September

The water temperature is 14°C (57°F) — chilly, but perfectly fine for a swim if you're not too sensitive to cold water. A short wetsuit can make longer sessions more comfortable.

If you prefer dry days with pleasant temperatures, June, July and August typically offer the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

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For a detailed overview over the year and the best time to visit Norway, check out our Oslo's climate page.

Oslo Temperature in September

Min Temperature 7°C (45°F)  

Max Temperature 16°C (61°F)  

Water Temperature 14°C (57°F)  

Chance of Rain 54%  

Precipitation 89 mm (3.5 in)  

Rainy days 16 days  

Humidity 76%  

Windspeed 2 m/s (4 knots)  

Sunshine 146 hours  

Percentage Sunshine  

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Oslo typically drop from around 17°C (63°F) at the start of September to approximately 13°C (55°F) by the end. Nights are cold, with lows typically ranging from 4°C (39°F) to 8°C (46°F).

Average temperatures in September

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Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

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Historical weather for Oslo in September

Browse day-by-day weather records for Oslo spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

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Oslo historical weather extremes in September

The extremes listed below come from historical weather data collected in Oslo from 1976 through 2025.

• Oslo recorded its highest September temperature of 26°C (79°F) on September 8, 2021.
• Oslo experienced its chilliest September day on September 25, 2013, reaching only 6°C (43°F).
• Oslo registered its coldest September night on September 27, 1986, with temperatures dropping to -6°C (21°F).
• The heaviest September precipitation occurred on September 2, 2015, when 52 mm (2 in) of precipitation fell.

What to Wear in Oslo in September

Pack for changing conditions in Oslo in September. Bring a mix of short and long sleeves, a warm layer like a hoodie or light jacket, and comfortable pants. The key is being able to add or remove layers as the days goes by. Prepare for significant rainfall with proper waterproof clothing and shoes. Expect water temperatures of around 14°C (57°F), which is definitely too cold for comfortable swimming. Your luggage space is better used for other items. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Oslo in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

5/10

Cycling

6/10

Walking

6/10

Camping

4/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Norway, check out our Oslo's climate page.

More climate data for Oslo

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Oslo climate overview or explore weather in Norway.