Oslo Temperature by Month

The average annual maximum temperature in Oslo, Oslo County, Norway is 10°C (50°F), with daytime highs ranging from -1°C (30°F) in January to 22°C (72°F) in July. This page covers monthly averages, day-night differences, and how Oslo compares to cities worldwide.

Visitors to Oslo will encounter a climate influenced by big temperature differences across the year. Nighttime temperatures range from 12°C (54°F) in July to -7°C (19°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Oslo by month:

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. July, the warmest month, averages 240 hours of sunshine.

The chart below shows the average temperature throughout the year:

Oslo's average annual maximum temperature is 10°C (50°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Queenstown, New Zealand averages 10°C (50°F) annually, remember seasons are flipped, so its coldest months fall in June and July.

San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation, summers are often cool and foggy, winters mild.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Oslo, January is the coolest month, with average highs of -1°C (30°F) and humidity around 84%, considered very high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Land Temperature: The average surface temperature across the Earth's land is around 14°C, but that figure hides enormous variation. In the Sahara, daytime temperatures can exceed 50°C. At the poles, averages fall below -30°C. Deserts are also notable for how quickly they cool at night, without moisture in the air to retain heat, temperatures can drop 30°C or more in just a few hours, making desert nights surprisingly cold.

Sea Temperature: The oceans average around 17°C at the surface, generally cooler than land. Because water absorbs and releases heat slowly, the sea acts as a buffer, keeping coastal climates more stable than inland areas. The deep ocean is a different story: below the sunlit upper layers, water stays near-freezing regardless of surface conditions.

Equatorial Regions: Near the equator, the sun is overhead year-round, producing consistent heat and fuelling tropical rainforests in places like the Amazon and Congo basins. Seasonal temperature variation is minimal, but these regions do experience distinct wet and dry seasons that shape their ecosystems.

Desert Regions: Desert temperatures swing wildly between seasons and even between day and night. The Sonoran Desert in North America can drop to 0°C on winter nights yet exceed 40°C on summer days. What all deserts share is very low rainfall, typically under 250mm per year.

Polar Regions: The Arctic and Antarctic experience extreme cold, with long stretches of darkness in winter and continuous daylight in summer. Arctic winter temperatures average around -30°C. In Antarctica's interior, it gets far colder, sometimes below -80°C in the coldest recorded spots.

Temperate Forests: Across North America, Europe, and East Asia, temperate forests see proper seasons, warm summers and cold winters, with average temperatures roughly between 5°C and 22°C depending on the time of year.

Mountain Regions: Temperature drops by roughly 6°C for every 1,000 metres of altitude. In ranges like the Andes or the Himalayas, that means you can move from temperate forest at lower elevations to permanent snow and ice at the peaks, all within a relatively short distance.

For more on Oslo's weather, including monthly rainfall, sunshine hours, and humidity, visit our Oslo climate page.