Summer in Helsinki brings long daylight hours, mild air, and a refreshing mix of coastal breezes. You’ll usually see average daytime highs around 18–22 °C (64–72 °F), so it’s comfortable without being sweltering.
Nights feel cooler, but the extended daylight, up to 18 hours in June, lets you enjoy the city outdoors for ages.
The season feels short, but it’s rewarding. June tends to start on the cooler side, July really turns up the warmth, and August quietly hints at autumn as temperatures dip a bit.
Rain showers happen pretty often, but they rarely stick around for long. The mix of sun and clouds creates a pleasant rhythm for exploring.
If you’re planning to spend time by the water, the Gulf of Finland warms up slowly, usually peaking late July or early August.
The sea stays cool compared to southern Europe, but plenty of locals still swim, sail, or just relax by the shoreline.
This balance of gentle warmth, fresh air, and light-filled evenings really sums up summer in Helsinki.
Overview of Helsinki’s Summer Climate
Helsinki’s summer brings mild to warm temperatures, loads of daylight, and a blend of sunshine and rain.
You’ll find the weather comfortable for outdoor activities, though it shifts between clear, blue skies and cloudy days, with moderate humidity and steady breezes off the Baltic Sea.
Typical Summer Temperatures
From June to August, daytime highs usually land between 19°C and 22°C (66°F–72°F).
July stands out as the warmest month, averaging around 18°C (64°F) overall.
Nights cool off, often dropping to 10°C–14°C (50°F–57°F), so a light jacket after sunset is a good idea.
Heatwaves don’t happen often, but they can pop up. Sometimes, daytime highs jump above 28°C (82°F), with the record hitting 33.2°C (91.8°F).
These hot spells don’t last, and cooler air tends to sweep in pretty quickly.
The long days are a big deal here. In June, daylight can stretch close to 19 hours, giving you tons of time outdoors.
By August, days get a bit shorter but still offer plenty of usable light.
| Month | Avg High °C | Avg Low °C | Avg Mean °C |
|---|---|---|---|
| June | 19.3 | 10.4 | 14.9 |
| July | 22.3 | 13.7 | 18.0 |
| August | 20.8 | 12.5 | 16.7 |
Seasonal Weather Patterns
Summer rainfall in Helsinki is moderate, with monthly averages between 55–80 mm.
Showers mostly arrive as light rain or quick thunderstorms, not long downpours.
August is usually the wettest month, while July is a bit drier.
Cloud cover is pretty common. On average, skies are overcast or mostly cloudy about 40–45% of the time.
Still, you’ll get several sunny days each month, especially in June and July.
Sunshine hours really ramp up compared to winter. You might see 9–10 hours of daily sunshine in midsummer, which is perfect for outdoor festivals, open-air dining, and waterfront fun.
The Baltic Sea stays cool. Surface water temperatures climb from about 9°C in June to 15–17°C in July and August.
Swimming might feel chilly, but it’s definitely refreshing.
Humidity and Wind Conditions
Humidity in Helsinki during summer usually sits at 65–75%, which feels pretty comfortable—nothing like the sticky air of the tropics.
Even on warmer days, the air rarely feels heavy.
Winds are steady but not wild. Average speeds hover around 11–12 kph (7–8 mph), usually blowing in from the southwest.
These breezes keep the air fresh and are great for sailing or boating along the coast.
Sometimes, evenings in July feel calm and still. When weather fronts pass through, wind speeds can pick up a bit, but strong storms are rare.
The maritime influence keeps the air crisp, especially near the shoreline.
This helps even out temperature swings and makes outdoor travel more pleasant.
Monthly Breakdown: June, July, and August
Helsinki’s summer brings long daylight hours, mild to warm temps, and a mix of dry and rainy days.
Conditions change from cooler early summer weather in June to the warmest days in July, then ease into slightly cooler, still pleasant conditions by August.
June Weather Highlights
June kicks off Helsinki’s warm season.
Average daytime highs hit about 19 °C (66 °F), and nights dip to around 10 °C (50 °F).
Evenings can feel chilly, so bring a light jacket.
The days are extra long, with nearly 19 hours of daylight around the solstice.
If you love outdoor activities, June is your month—you can explore late into the night.
Rainfall averages 60 mm over about 9 days.
Showers are typically brief, but you’ll want to keep an umbrella handy.
The Baltic Sea is still cold, about 9 °C (48 °F), so swimming isn’t exactly inviting yet.
That said, the mild air and long days make June a lively time for festivals and outdoor events.
July Weather Highlights
July is the warmest month in Helsinki.
Average highs reach 22 °C (72 °F), and lows hover near 14 °C (57 °F).
Some days get warmer, climbing above 27 °C (81 °F), but those heatwaves don’t stick around.
Daylight remains long, with about 18 hours early in the month.
You can hang out in parks, visit islands, or stroll the waterfront well into the evening.
Rainfall is moderate at 55 mm across about 7 days.
Showers happen less often than in June or August, making July one of the drier summer months.
The sea warms up to around 15 °C (59 °F).
While that’s still cool, plenty of locals and visitors go for a swim.
You’ll also notice higher humidity levels, which can make warm days feel a bit heavier.
August Weather Highlights
August brings slightly cooler conditions but still feels comfortable.
Average highs reach 21 °C (70 °F), and lows drop to 13 °C (55 °F).
Nights start to feel a bit brisk, hinting that autumn’s on the way.
Rainfall increases to about 80 mm over 10 days, making August the wettest summer month.
Showers can be heavier, so waterproof clothing is a good call.
Daylight shortens to about 15 hours by mid-month.
Evenings come earlier, but you’ve still got loads of time for outdoor plans.
Sea temperatures peak around 17 °C (63 °F), so August is the best month for swimming in Helsinki.
Pair that with mild air and late-summer events, and it’s a popular time for visitors who want a calmer vibe than July.
Rainfall and Sunshine During Summer
Helsinki’s summer brings moderate rainfall and long days.
You’ll get a mix of clear, sunny skies and occasional showers, so it’s easy to enjoy both outdoor activities and sightseeing.
Average Precipitation Levels
Rainfall in Helsinki during summer stays steady but never gets extreme.
June usually sees around 40–60 mm of rain, July about 60–65 mm, and August tops out at 70–80 mm.
August is typically the wettest summer month, while June is a bit drier.
Rain usually falls as light to moderate showers, not heavy downpours.
Compared to other European capitals, Helsinki’s summer rainfall is pretty average.
You’ll want to plan for some rain, but it rarely ruins a whole day.
Number of Rainy Days
Rainy days in summer are fairly balanced.
You can expect about 10–13 days with measurable rain each month from June through August.
Showers tend to pass quickly, leaving dry stretches in between.
This pattern means you can still enjoy outdoor events and sightseeing—even if rain pops up in the forecast.
Rainfall spreads out over the month, so long runs of rainy days are uncommon.
Packing a light rain jacket or umbrella is usually enough.
Sunshine Hours and Daylight
Summer in Helsinki is all about long days and extended sunlight.
In June, daylight can last 18–19 hours, so you get nearly full days of brightness.
July averages about 17–18 hours, and August still offers 15–16 hours.
Actual sunshine hours (when the sun’s visible) average around 8–10 hours per day in June and July.
August dips just a bit due to more clouds.
This abundance of daylight is perfect for outdoor activities.
You can plan sightseeing, walking tours, or time by the sea well into the evening without feeling rushed.
Sea Temperatures and Coastal Conditions
The waters around Helsinki warm up slowly through spring, peaking in mid to late summer.
Coastal conditions feel refreshing, and the sea shapes both recreation and comfort during the season.
Baltic Sea Water Temperatures
The Gulf of Finland, where Helsinki sits, shows a pretty wide seasonal range.
In June, water temperatures usually hover near 10–16°C (50–61°F).
By July and early August, the sea often hits 17–19°C (63–66°F), which is as warm as it gets all year.
Late August and September bring a slow cool-down, with averages closer to 14–16°C (57–61°F).
That’s still swimmable for many, but you’ll notice the chill compared to midsummer.
Shallow coastal areas and sheltered bays warm up faster than the open sea.
You might find water a few degrees warmer near beaches, especially on sunny, calm days.
| Month | Avg Min °C | Avg Max °C |
|---|---|---|
| June | 10–12 | 16–17 |
| July | 15–17 | 18–19 |
| August | 14–15 | 18–19 |
These temperatures are long-term averages and can shift with wind direction, cloud cover, or the timing of summer heatwaves.
Swimming and Outdoor Activities
Swimming in Helsinki is possible all summer, but it depends on how much you like cool water.
In July, lots of locals and visitors swim comfortably without wetsuits.
Earlier in June or later in September, a quick dip might feel bracing unless you’re used to colder seas.
Public beaches like Hietaniemi (Hietsu) and Aurinkolahti fill up in warm weather.
These spots usually have warmer shallows, making them great for families.
If you’re into water sports like kayaking or paddleboarding, summer brings stable conditions.
Winds are usually moderate, though breezier days can kick up small waves along exposed shores.
For longer swims or open-water training, a thin wetsuit helps, especially outside July and August.
It lets you stay in the water longer and enjoy the coastal scenery.
Best Time to Visit Helsinki in Summer
Summer in Helsinki gives you the mildest weather of the year, with long daylight and comfortable temperatures.
You can enjoy outdoor activities, cultural events, and the city’s coastal scenery without the bite of winter or the short days of autumn.
Ideal Months for Travel
The best time to visit Helsinki in summer is June through August.
During this stretch, average highs run from 19°C to 23°C (66°F to 73°F), while evenings cool off to 12°C to 15°C (54°F to 59°F).
June marks the start of the warm season and brings the longest days of the year, with up to 18 hours of daylight.
July is usually the warmest month, and the sea reaches about 15–16°C (59–61°F), which is the most comfortable time for swimming or boating.
August stays pleasant but is a bit cooler, with more rain than June or July.
If you like fewer crowds and don’t mind occasional showers, August strikes a nice balance between warm weather and quieter attractions.
Events and Activities
Helsinki’s summer calendar bursts with festivals, concerts, and outdoor gatherings. In June, you’ll get to experience Midsummer (Juhannus)—a major Finnish holiday. People celebrate with bonfires, music, and time by the sea or out on the islands.
July brings a wave of open-air concerts, food festivals, and waterfront events. Locals love spending time outside, so expect lively cafés, bustling markets, and parks full of people enjoying the sunshine.
August doesn’t slow down. The Helsinki Festival takes over the city, and it’s Finland’s biggest arts festival. You’ll catch theater, dance, and music performances all over town.
Late summer feels perfect for wandering along the archipelago or hopping on a ferry to Suomenlinna. The weather stays mild, and the crowds start to thin out—finally, you can breathe a little.
Packing Tips for Helsinki’s Summer Weather
Helsinki’s summer stays mostly mild, but honestly, you never quite know what you’ll get. Warm afternoons can turn into cool evenings, and rain showers might pop up out of nowhere. It’s best to prepare for both sunshine and sudden temperature shifts. Pick clothing and accessories that keep you comfortable and ready for the elements.
Recommended Clothing
Average summer temperatures in Helsinki usually fall between 15–25°C (59–77°F). Lightweight clothes work great during the day. When the sun sets, you’ll want layers.
Pack breathable shirts, a light sweater, and a jacket. This mix keeps things simple and flexible, so you won’t overpack.
Toss in cotton or linen T-shirts and a few long-sleeve tops for cooler evenings or extra sun protection. Near the coast, a windbreaker or light waterproof jacket comes in handy since breezes and showers happen pretty often.
For bottoms, bring comfortable pants, shorts, or skirts—something you can walk in for hours. If you’re planning to eat out, a casual dress or smart outfit works well. Locals usually dress up a bit in the evenings.
Don’t forget practical shoes. Comfortable walking shoes make city exploring so much easier. Sandals are nice for the warmer days. And if you’re thinking about a swim in the Baltic Sea or a nearby lake, definitely pack swimwear.
Essential Accessories
Finland’s long daylight hours might mess with your sleep. I’d recommend a sleep mask to block out the light during those bright nights.
You’ll want sunglasses and a sun hat—the sunlight can get intense, especially by the water or in wide-open parks.
Rain shows up more often than you’d expect, so toss in a compact umbrella or a foldable rain jacket.
A reusable shopping bag comes in handy too, since shops usually charge for plastic bags.
Mosquitoes love hanging out in parks and near lakes, so bring some insect repellent.
If you’re heading outside the city, I’d suggest packing a portable charger and a lightweight towel for those spontaneous day trips.
Don’t forget sunscreen and lip balm with SPF—your skin still needs it, even if the sky looks cloudy.