Oslo records about 763mm of rain across roughly 150 wet days a year, which is a 41% chance on an average day. September is the wettest month at 90mm (12% of the annual total) and February the driest at 41mm. Local rain type: steady rain. Always carry waterproof layers. Oslo rain shifts to snow from November through March. A waterproof shell jacket is more practical than an umbrella in Norwegian weather.
Chance of rain on an average day: 41%
Rainfall climatology for Oslo. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 763mm |
| Rain days per year | 150 |
| Odds on an average day | 41% |
| Wettest month | September — 90mm over 18 days |
| Driest month | February — 41mm over 8 days |
| Rain type | steady rain |
| Best dry window | May and June offer the driest conditions combined with long Scandinavian summer days. |
| Worst rain window | August through October brings the wettest months, often with grey overcast skies. |
September delivers 120% more rain than February (90mm vs 41mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 12% of the annual total, so rain in Oslo is spread through the year — there is no season you can rely on being dry.
Oslo rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 18 days in September against 8 in February — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 54mm | 11 | 37% | 0°C |
| February | 41mm | 8 | 27% | 0°C |
| March | 47mm | 9 | 30% | 3°C |
| April | 42mm | 8 | 27% | 8°C |
| May | 53mm | 10 | 33% | 14°C |
| June | 65mm | 13 | 43% | 19°C |
| July | 81mm | 16 | 53% | 22°C |
| August | 89mm | 17 | 57% | 22°C |
| September | 90mm | 18 | 60% | 19°C |
| October | 84mm | 16 | 53% | 14°C |
| November | 73mm | 14 | 47% | 8°C |
| December | 52mm | 10 | 33% | 3°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Oslo we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Oslo records rain on roughly 150 days a year — about a 41% chance on any given day — totalling around 763mm.
September, with about 90mm over 18 rain days. That is 12% of the entire year's rainfall in a single month.
February is the driest month at 41mm across roughly 8 days. May and June offer the driest conditions combined with long Scandinavian summer days.
Always carry waterproof layers. Oslo rain shifts to snow from November through March. A waterproof shell jacket is more practical than an umbrella in Norwegian weather.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.