Helsinki records about 655mm of rain across roughly 117 wet days a year, which is a 32% chance on an average day. August is the wettest month at 80mm (12% of the annual total) and April the driest at 34mm. Local rain type: snow mix. Helsinki rain peaks in late summer, while winter brings snow instead. Waterproof boots are essential from November through March for slush and ice.
Chance of rain on an average day: 32%
Rainfall climatology for Helsinki. 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 | 655mm |
| Rain days per year | 117 |
| Odds on an average day | 32% |
| Wettest month | August — 80mm over 14 days |
| Driest month | April — 34mm over 6 days |
| Rain type | snow mix |
| Best dry window | June offers the driest weather combined with the magical white nights — nearly 24 hours of daylight. |
| Worst rain window | August and September bring the heaviest rain, while November starts the transition to snow. |
August delivers 135% more rain than April (80mm vs 34mm). 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 Helsinki is spread through the year — there is no season you can rely on being dry.
Helsinki rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 14 days in August against 6 in April — 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 | 47mm | 8 | 27% | -1°C |
| February | 36mm | 6 | 20% | -1°C |
| March | 37mm | 7 | 23% | 2°C |
| April | 34mm | 6 | 20% | 8°C |
| May | 38mm | 7 | 23% | 13°C |
| June | 57mm | 10 | 33% | 19°C |
| July | 64mm | 11 | 37% | 22°C |
| August | 80mm | 14 | 47% | 22°C |
| September | 65mm | 12 | 40% | 19°C |
| October | 76mm | 14 | 47% | 13°C |
| November | 64mm | 11 | 37% | 8°C |
| December | 55mm | 10 | 33% | 2°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Helsinki 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.
Helsinki records rain on roughly 117 days a year — about a 32% chance on any given day — totalling around 655mm.
August, with about 80mm over 14 rain days. That is 12% of the entire year's rainfall in a single month.
April is the driest month at 34mm across roughly 6 days. June offers the driest weather combined with the magical white nights — nearly 24 hours of daylight.
Helsinki rain peaks in late summer, while winter brings snow instead. Waterproof boots are essential from November through March for slush and ice.
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.