Climate and monthly weather forecast
Porvoo, Finland

The city of Porvoo, Finland, is located in the Dfb Koppen Climate zone, which is characterized as a humid continental climate, lacking a dry season, but with warm summers. Under the umbrella of geographical position, Porvoo experiences a diverse range of climatological parameters which exhibit palpable shifts from month to month.

An analysis of climatological data reveals a significant variation in the parameters from January to December. Monthly sea temperatures vary widely throughout the year, with the mercury touching as high as 18.7°C (65.7°F) in the peak of summer, July and August, and dipping down to -0.2°C (31.6°F) in the dead of winter, hitting rock bottom in January and February.

Daylight hours also experience a broad range of fluctuations throughout the year, with the longest daylight span being reported in June, at 18.9 hours, while the shortest days are experienced in December at nearly 5.9 hours. The change in daylight conditions generates a noticeable oscillation in the visual aspect of the city throughout the various months.

The city possesses a unique pattern where there is intense contrast between the continually cold and dark winter months and warm, luminous summer months. The sea temperature peaks during July and August, rendering them the warmest months.

The ideal period to experience the best aspects of Porvoo’s climate would be from June to August. During these months, the city is bathed in nearly 18.9 hours of daylight in June, while sea temperatures hover from 13.1°C (55.6°F) to 18.7°C (65.7°F), providing delightful weather for outdoor activities. These conditions allow for sightseeing, trailing the local landmarks, and partaking in recreational activities.

Visitors may want to avoid January and February, as temperatures can plunge to -0.2°C (31.6°F) and daylight is limited to about 6.8 to 9.1 hours. These are the coldest and darkest months, resulting in constraints on outdoor exploration and activities.

Springtime in Porvoo, falling from March to May, witnesses a perceptible shift in climatological parameters. Sea temperatures begin to rise from -0.2°C (31.6°F) to 6.9°C (44.4°F). Daylight span increases substantially from 11.8 hours in March to 17.3 hours in May, indicating longer and warmer days ahead.

Summer follows spring, starting from June and ending in August, with climatic conditions reaching optimal levels. Sea temperatures range from 13.1°C (55.6°F) to 18.7°C (65.7°F), while daylight hours climb up to a bountiful 18.9 hours in June, before slightly diminishing to 18.1 hours in July and 15.6 hours in August.

In autumn, which spans from September to November, a decline in climatological parameters is noted. Sea temperatures start falling, moving from 15.1°C (59.2°F) down to 6.7°C (44.1°F). The daylight span also reduces from 12.9 hours to 7.5 hours over these months, marking the transition towards the colder months of the year.

Winter in Porvoo encompasses December to February. During this season, sea temperatures continue to descend even further, registering values from 3.6°C (38.5°F) in December to -0.2°C (31.6°F) in February. Daylight hours experience a drastic fall, reaching their lowest at 5.9 hours in December, laying the foundation for chilly and dark winter days.

Starting the year with January, Porvoo, Finland experiences quite low sea temperatures with an average measurement of 0.5°C (32.9°F). This month marks the heart of winter, a time when daylight hours are limited and the city takes on its calm, winter persona. Weather in January »

Moving to February, the weather in Porvoo takes on a relatively colder demeanor, with sea temperatures slightly declining to -0.2°C (31.6°F). While much akin to January, the difference lies in the gradually increasing daylight hours. Weather in February »

March ushers in subtle changes in the weather as Porvoo progressively moves towards spring. Sea temperatures remain constant at -0.2°C (31.6°F) - reflecting February's cool climes. The city starts to awaken from the long winter as daylight hours extend further. Weather in March »

April sees the first substantial increase in sea temperatures to 1.5°C (34.7°F), signaling the impending warmth of spring. The landscape of Porvoo undergoes a visible transformation as winter snow melts away completely. New plant life flourishes across the city, painting streets and parks in vibrant hues of green. Weather in April »

May brings the unmistakable signs of spring with sea temperatures jumping sharply to 6.9°C (44.4°F). The shift to warmer weather opens up fresh possibilities for residents and tourists in Porvoo. Food festivals, art exhibitions and a host of outdoor activities pick up, injecting life into the city’s vibrant cultural scene. Weather in May »

June witnesses the highest leap in sea temperatures from May, with averages now reaching 13.1°C (55.6°F). Porvoo adopts its sunny summer façade during this period. The city bathes in maximal daylight hours, offering visitors and locals plenty of time to explore or indulge in recreational activities. Weather in June »

At the heart of summer, July experiences the highest sea temperature of the year at 18.7°C (65.7°F) in Porvoo. Despite a slight decrease in daylight from the preceding month, the days are still long and bright. The sun-drenched city, adorned in summer blooms, invites residents to outdoor picnics, hikes, and water sports. Weather in July »

August maintains July’s sea temperature, remaining at 18.7°C (65.7°F) but witnesses a gradual shortening of daylight hours. Nevertheless, the settled summer weather makes for ideal conditions to explore Porvoo's famed medieval wooden houses. Weather in August »

September witnesses a drop in sea temperatures to 15.1°C (59.2°F), hinting at the onset of autumn. The changing season colours Porvoo's streets and parks in beautiful shades of orange and red. Despite the cooling weather, outdoor activities remain popular, particularly hiking and cycling. Weather in September »

October brings a significant decrease in sea temperatures marking it at 10.3°C (50.5°F), reflecting the deepening autumn in Porvoo. The daylight hours start to diminish significantly, but the city continues to bristle with activity. Weather in October »

The weather turns colder in November, as the sea temperatures fall to 6.7°C (44.1°F), ushering in the transition from autumn to winter. Porvoo gears up for the Christmas season, with shops starting to sell festive decor and local eateries introducing winter-themed menus. Weather in November »

December holds the reigns of winter firmly with sea temperatures dropping down to 3.6°C (38.5°F). Porvoo adapts seamlessly to the winter, with streets brightened by Christmas lights and markets offering an array of festive goods. Weather in December »