Trolltunga records about 1650mm of rain across roughly 210 wet days a year, which is a 58% chance on an average day. October is the wettest month at 210mm (13% of the annual total) and May the driest at 80mm. Local rain type: steady rain. Full alpine waterproof gear is mandatory for the 10-12 hour hike. Rain, snow, and fog can all occur on the same day, even in summer. Pack for every scenario — the weather changes hourly.
Chance of rain on an average day: 58%
Rainfall climatology for Trolltunga. 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.
Conditions on this page are recalculated from the latest forecast every time it is opened, for the current date in the location's own time zone. Showing .
| Annual rainfall | 1650mm |
| Rain days per year | 210 |
| Odds on an average day | 58% |
| Wettest month | October — 210mm over 26 days |
| Driest month | May — 80mm over 10 days |
| Rain type | steady rain |
| Best dry window | Late June through July offers the most stable weather and longest days for the demanding hike. |
| Worst rain window | October brings relentless rain and early snow — the trail is officially closed from November to June due to dangerous conditions. |
October delivers 163% more rain than May (210mm vs 80mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 13% of the annual total, so rain in Trolltunga is spread through the year — there is no season you can rely on being dry.
Trolltunga rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 26 days in October against 10 in May — 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 | 160mm | 20 | 67% | 2°C |
| February | 120mm | 15 | 50% | 2°C |
| March | 125mm | 16 | 53% | 4°C |
| April | 100mm | 13 | 43% | 7°C |
| May | 80mm | 10 | 33% | 11°C |
| June | 90mm | 11 | 37% | 14°C |
| July | 110mm | 14 | 47% | 16°C |
| August | 140mm | 18 | 60% | 16°C |
| September | 180mm | 23 | 77% | 14°C |
| October | 210mm | 26 | 87% | 11°C |
| November | 190mm | 24 | 80% | 7°C |
| December | 175mm | 22 | 73% | 4°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Trolltunga 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.
Trolltunga records rain on roughly 210 days a year — about a 58% chance on any given day — totalling around 1650mm.
October, with about 210mm over 26 rain days. That is 13% of the entire year's rainfall in a single month.
May is the driest month at 80mm across roughly 10 days. Late June through July offers the most stable weather and longest days for the demanding hike.
Full alpine waterproof gear is mandatory for the 10-12 hour hike. Rain, snow, and fog can all occur on the same day, even in summer. Pack for every scenario — the weather changes hourly.
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.