Question 1

When is the sunniest time of year in Oslo?

Accepted Answer

The sunniest time of year in Oslo is late spring through summer, with July being the brightest month of 2025 at 312.5 hours of sunshine — roughly 10 hours of sun per day.

Oslo's high northern latitude creates dramatic seasonal swings in daylight, and the 2025 data shows this clearly. The brightest stretch ran from May to August, when the city recorded 1,201 sunshine hours — about 53% of its entire annual total of 2,265 hours. May (305.9 hours) and August (306.8 hours) were nearly as bright as July, so the sunny season is broad rather than a single peak.

These long, luminous days coincided with Oslo's mildest weather. July 2025 was also the warmest month, averaging 19.0°C (66.2°F) with a high of 29.9°C (85.8°F), while May and June brought comfortable averages of 10.5°C (50.9°F) and 13.6°C (56.5°F). The trade-off is that summer is not the driest period: July still saw 70.5mm of rain, so brief showers are possible even during the sunniest weeks.

The contrast with winter is stark. November 2025 was the darkest month at just 44.8 hours of sunshine — about 1.5 hours per day — followed by January with 65.1 hours.

If you want to experience Oslo at its brightest, plan a visit between May and August. This window combines the long Nordic daylight with the year's warmest temperatures, making it ideal for hiking, exploring the fjord, and enjoying the city's outdoor cafés.

Question 2

How cold does Oslo get in winter?

Accepted Answer

Oslo gets reliably cold and frosty in winter, with an average temperature of around **−2.3°C (27.8°F)** during Winter 2024/25 (December 2024 to February 2025). The Norwegian capital stays below freezing for much of the season, so sub-zero days are the norm rather than the exception.

The coldest reading of the season came in January 2025, when temperatures in Oslo dropped to **−15.3°C (4.5°F)**. January was also the chilliest month overall, with a monthly mean of −3.2°C (26.2°F), followed closely by February at −3.0°C (26.6°F). December 2024 was milder at −0.8°C (30.6°F) and even briefly touched a thaw, with a seasonal high of **8.7°C (47.7°F)**.

Winter in Oslo is damp as well as cold. The city recorded **128.5mm (5.1 in)** of total precipitation across the three months, with average humidity near 83% and light winds averaging just 8.7 km/h (5.4 mph). The calm, moist, sub-freezing air helps keep snow and frost on the ground through much of the season.

For visitors, this means Oslo winters call for serious cold-weather gear: insulated layers, a windproof coat, gloves, and waterproof boots. The combination of consistent freezing temperatures and modest wind makes conditions feel crisp rather than harsh, and the long, cold spells are ideal for winter activities like cross-country skiing, ice skating, and exploring the city's snow-dusted streets.

Question 3

Which season is the wettest in Oslo?

Accepted Answer

Autumn is the wettest season in Oslo, with the city recording 222.1 mm (8.7 in) of precipitation during autumn 2025 (September to November) — more than any other meteorological season.

Across the full 2025 calendar year, Oslo received 634.8 mm (25.0 in) of total precipitation. Breaking this down by meteorological season shows a clear autumn peak:

- **Autumn (Sep–Nov 2025):** 222.1 mm (8.7 in)
- **Summer (Jun–Aug 2025):** 191.8 mm (7.6 in)
- **Winter (Jan, Feb & Dec 2025):** 126.4 mm (5.0 in)
- **Spring (Mar–May 2025):** 94.5 mm (3.7 in)

Autumn alone accounted for roughly 35% of Oslo's annual rainfall in 2025. The single wettest month was November 2025 with 84.6 mm (3.3 in), while March 2025 was the driest at just 11.3 mm (0.4 in). Note that within a single calendar year, meteorological winter covers January, February, and December; a complete winter season (such as Winter 2024/25, December 2024 to February 2025) spans two calendar years.

For visitors and residents, this means Oslo's autumn months bring the most consistent wet weather, so a waterproof jacket and umbrella are essential from September through November. Spring, by contrast, is noticeably drier, making March to May the better window for outdoor plans if you want to avoid the rain in Oslo.

Question 4

What were the temperature extremes in Oslo in 2025?

Accepted Answer

Oslo's temperature extremes in 2025 ranged from a high of **29.9°C (85.8°F)** on 20 July to a low of **-15.3°C (4.5°F)** on 5 January, giving the city an annual temperature swing of about 45°C (81°F).

The hottest stretch came in mid-summer, when Oslo recorded 13 days with highs of 25°C (77°F) or above, though no day in 2025 reached 30°C (86°F). The coldest spell hit in early January: the lowest daily average of the year was -12.0°C (10.4°F) on 4 January, and 12 days saw lows of -10°C (14°F) or colder. Across the full year, Oslo averaged a mean temperature of **7.0°C (44.6°F)**.

Winter cold was a persistent feature in 2025. The city logged 126 days with sub-zero (below 0°C / 32°F) overnight lows and 45 "ice days" where the temperature never climbed above freezing.

For visitors, this wide range means Oslo demands very different packing depending on the season. Plan for genuine warmth and long daylight in July, but expect hard frost, ice, and the need for serious winter gear from December through February. The pleasant shoulder months of spring and autumn sit comfortably between these two extremes.

Question 5

What is the weather like in Oslo in July?

Accepted Answer

July is the warmest and sunniest month of the year in Oslo, with comfortably mild summer temperatures and long daylight hours. In July 2025, Oslo averaged a mean temperature of 19.0°C (66.2°F), making it an excellent time to visit the Norwegian capital.

During July 2025, daytime highs in Oslo averaged 23.5°C (74.3°F), while nights stayed mild at around 14.2°C (57.6°F). The warmth peaked on July 20, when the temperature reached 29.9°C (85.8°F), and the city enjoyed 13 days with highs of 25°C (77°F) or more. Even the coolest night only dipped to 9.0°C (48.2°F).

Other key July 2025 figures for Oslo:

- **Sunshine:** 312.5 hours total, roughly 10.1 hours per day on average
- **Rainfall:** 70.3 mm (2.8 in) over the month
- **Rainy days:** 14 days with measurable rain (1 mm or more)

These conditions make July one of the best months for outdoor activities in Oslo, from harbour-side dining to hiking in the surrounding forested hills. Visitors should still pack a light rain jacket, however, as showers fell on roughly half the days, often mixed in between long, bright sunny spells. Overall, July offers Oslo's most reliable summer warmth and abundant daylight, ideal for exploring the city and the nearby Oslofjord.

Diakonissehuset

Oslo

FAQ

When is the sunniest time of year in Oslo?

How cold does Oslo get in winter?

Which season is the wettest in Oslo?

What were the temperature extremes in Oslo in 2025?

What is the weather like in Oslo in July?