Oslo Climate — Average Highs, Lows & Rainfall by Month
Oslo has a temperate climate with four distinct seasons. Daytime temperatures average 21°C / 71°F in July, the warmest month, and drop to -1°C / 30°F in January, the coldest. Overnight lows in January average -6°C / 20°F. Oslo receives about 919 mm of rain a year across roughly 130 wet days, with July the wettest month.
Averages for 2021–2025 · Open-Meteo Historical Weather API (ERA5 reanalysis) · Updated 2026-10-05
Monthly averages in Oslo
Average daytime high, overnight low and rainfall for each month of the year.
| Month | Avg high | Avg low | Rainfall | Wet days |
|---|---|---|---|---|
| January | -1°C / 30°F | -6°C / 20°F | 77 mm | 10 |
| February | 1°C / 33°F | -5°C / 23°F | 54 mm | 11 |
| March | 6°C / 42°F | -2°C / 28°F | 46 mm | 8 |
| April | 10°C / 51°F | 1°C / 34°F | 49 mm | 8 |
| May | 17°C / 62°F | 7°C / 44°F | 64 mm | 11 |
| June | 21°C / 69°F | 12°C / 53°F | 85 mm | 11 |
| July | 21°C / 71°F | 14°C / 57°F | 145 mm | 14 |
| August | 20°C / 68°F | 12°C / 54°F | 96 mm | 12 |
| September | 16°C / 61°F | 10°C / 49°F | 95 mm | 11 |
| October | 10°C / 50°F | 5°C / 41°F | 84 mm | 12 |
| November | 4°C / 39°F | 0°C / 32°F | 66 mm | 11 |
| December | 0°C / 31°F | -5°C / 24°F | 58 mm | 11 |
Best time to visit Oslo
June, August, July offer the most comfortable weather in Oslo: mild daytime temperatures with the year's lowest rainfall — June averages 21°C (69°F); August averages 20°C (68°F); July averages 21°C (71°F).
Oslo climate FAQ
- What is the hottest month in Oslo?
- July is the hottest month in Oslo, with average daytime highs of 21°C / 71°F and overnight lows of 14°C / 57°F (averages for 2021–2025).
- What is the coldest month in Oslo?
- January is the coldest month in Oslo, with average highs of -1°C / 30°F and lows of -6°C / 20°F.
- How much rain does Oslo get a year?
- Oslo receives about 919 mm of rainfall a year, spread over roughly 130 wet days. July is the wettest month (145 mm on average) and March the driest (46 mm).
- When is the best time to visit Oslo?
- June, August, July are the most comfortable months in Oslo: mild daytime temperatures with the least rainfall of the year.
Want today's conditions instead of averages?
See live weather in Oslo →Source: Open-Meteo Historical Weather API (ERA5 reanalysis), Open-Meteo. Averages are daily means across 2021–2025 and are rounded for display — for a live forecast see the Oslo weather page.