The best time to visit Oslo is June, July and August, when average highs sit in a comfortable band — 21.2 °C in June, 22.2 °C in July and 20.3 °C in August — paired with the longest, brightest days of the year. July and August fall within Norwegian school holidays, making them the busiest and priciest weeks in the city, while June often delivers similar warmth with slightly thinner crowds. Winter, from December through February, is the quiet low season, with highs near or below freezing and as little as 1.9 hours of sunshine a day in December.
Best months JuneJulyAugust
Oslo month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sun / day |
|---|---|---|---|---|
| January | -0.2 °C | -5.4 °C | 11 | 2.7 h |
| February | 1.5 °C | -4.3 °C | 10 | 4.8 h |
| March | 5.5 °C | -2 °C | 9 | 7.2 h |
| April | 11 °C | 1.9 °C | 8 | 10.2 h |
| May | 16.9 °C | 7.5 °C | 11 | 12 h |
| June | 21.2 °C | 12.4 °C | 12 | 13 h |
| July | 22.2 °C | 14 °C | 13 | 12.6 h |
| August | 20.3 °C | 13 °C | 13 | 10.3 h |
| September | 16.7 °C | 10.3 °C | 11 | 7.5 h |
| October | 10.2 °C | 5.2 °C | 13 | 4.9 h |
| November | 4.6 °C | 0.8 °C | 12 | 2.5 h |
| December | 1.2 °C | -3 °C | 13 | 1.9 h |
How the months are picked.A month qualifies when its average high sits in the comfortable 20–28 °C band (scored down towards 9 °C and 37 °C), rain days are few and sunshine hours are high — at least 78 % of the city's best-scoring month. July and August are then set aside as peak season (school-holiday crowds and prices) whenever at least three other months qualify; where summer is the only comfortable window they stay. Figures are ten-year averages (2016-01-01 to 2025-12-31) from ERA5 reanalysis data via Open-Meteo (CC BY 4.0) for the city centre coordinates.
When to go, and what to expect
Spring (Mar–May)
Good for travellers who want mild days, greening parks and fewer crowds before summer.
Summer (Jun–Aug)
The prime window for the harbour, islands and the Opera House rooftop — book ahead.
Autumn (Sep–Nov)
Best for early September, when it stays mild before the dark, damp turn.
Winter (Dec–Feb)
Worth it for snow, museums and holiday markets if you don't mind short days.
Notable events
- 17 May
- Constitution Day (Syttende Mai)
- August
- Øya Festival
- December
- Oslo Christmas Markets (Jul Marked)
- December
- Nobel Peace Prize Ceremony
Frequently asked
Is Oslo too hot in August?
No. August highs average 20.3 °C, comfortably within the pleasant band, though there are 13 rain days, so pack a light layer and a jacket.
What is the rainiest month in Oslo?
Rain days peak in the low teens across summer and autumn — July, August, October and December each see 13 rain days, so showers are possible year-round.
Is winter worth visiting Oslo?
It's quiet and atmospheric but dark and cold: December highs reach just 1.2 °C with only 1.9 hours of sunshine a day. Go for Christmas markets and snow, not for daylight.
Know when to go? Now decide where to stay — our Oslo area guide →
Areas of Oslo
Best time to visit near here
Sources
- Open-Meteo historical weather API — monthly climate normals, 2016–2025 (CC BY 4.0)
- ERA5 reanalysis (ECMWF / Copernicus) — the underlying temperature, precipitation and sunshine data
- ReasonStay methodology — how the best months are computed and checked
An independent guide to Oslo — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.