May Weather in Lahti, Finland

Last updated: August 21, 2025

In Lahti, Finland, May brings a diverse range of weather, with temperatures swinging from a brisk minimum of -3°C (27°F) to a warm maximum of 28°C (83°F). The average temperature hovers around a comfortable 10°C (50°F), making it a pleasant time to enjoy the outdoors. However, residents and visitors should be prepared for some rain, as the month sees approximately 54 mm (2.1 in) of precipitation over 10 days. With humidity levels averaging 75%, the air can feel quite refreshing, contributing to the vibrant spring atmosphere in this picturesque city.

May Temperature in Lahti

In May, Lahti, Finland, emerges from the clutches of winter as temperatures begin to rise, bringing a refreshing change. With a minimum temperature of -3°C (27°F) and a pleasant average of 10°C (50°F), the city starts to experience the warmth of spring. The maximum temperature can reach an exhilarating 28°C (83°F), allowing for longer, sunnier days that entice residents outdoors. This significant shift from the chilly months preceding it, where temperatures barely nudged above freezing, showcases a delightful trend towards warmth and vitality. May marks a period of renewal in Lahti, inviting everyone to embrace the beauty of nature as the season blossoms.

May Weather in Lahti: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Lahti, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lahti, May typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec252329385061636152433628
Data source: Temperature data for Lahti generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Lahti

In May, Lahti, Finland experiences a noticeable uptick in precipitation, with an average of 54 mm (2.1 in) across 10 days of rainfall. This marks a slight increase from April's 48 mm (1.9 in), hinting at the city's transition into the lush, verdant landscapes of late spring. While May's precipitation slightly lags behind the wetter months of June and July, it provides essential moisture, setting the stage for the vibrant summer blooms to come. Notably, the number of rainy days remains consistent with that of the previous months, creating a steady rhythm of showers that enrich the region's natural beauty. This trend underscores the importance of precipitation in fostering Lahti's unique and thriving ecosystem.

May Precipitation Trends in Lahti

The chart displays monthly precipitation patterns in Lahti, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Lahti, May typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec494545485463778062785471
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Lahti

In May, Lahti, Finland, experiences a noticeable shift in humidity levels, dropping to 75% from the higher percentages seen in the preceding months. This decline marks a significant transition as residents welcome warmer days, moving away from the winter's heavy, moisture-laden air that lingers through the early months of the year. As spring progresses, the humidity continues to decrease slightly into June, settling at 74%. This pattern suggests a gradual easing of moisture in the atmosphere, paving the way for the summer season. The comfortable humidity levels in May invite outdoor activities and blossoming nature, showcasing the vibrant beauty of Lahti as it emerges from the chill of winter.

May Average Humidity in Lahti

This chart illustrates the average monthly humidity levels in Lahti, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Lahti is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec98%96%93%87%75%74%80%85%90%94%94%96%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Lahti

As we transition into May in Lahti, Finland, the UV Index reaches 5, indicating a moderate level of sun exposure. This marks an increase from the lower indices seen during the winter months—in January and February, the UV Index is a mere 1, which is categorized as low. As spring progresses, there's a noticeable rise in UV levels, moving to 3 in March and 4 in April, reflecting the longer days and increased sunlight. In May, outdoor enthusiasts should be mindful of their exposure, as the recommended burn time drops to 30 minutes. With summer on the horizon, it's essential to stay informed about UV trends to protect your skin while enjoying the outdoors. For detailed insights, visit Lahti UV Index.

Maximum UV Index Levels in Lahti for May

The chart shows the monthly maximum UV Index (UVI) for Lahti in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Lahti typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113456753211
Data source: Lahti May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Lahti

As spring blossoms into summer, Lahti, Finland, revels in a dramatic increase in sunshine hours. Starting from a mere 44 hours in January, the days gradually brighten, culminating in a vibrant 429 hours of sunlight in May. This month marks the peak of spring brightness, as nature awakens and the city basks in longer, sunnier days, paving the way for the 475 hours that June will bring. The upward trend throughout these early months reflects not just a shift in the weather, but also a growing anticipation for the outdoor activities and rich cultural experiences that accompany the radiant Finnish summer. As the daylight hours begin to wane after July, May's luminosity leaves a lasting impression, beckoning locals and visitors alike to soak in the sun-drenched beauty of Lahti.

Monthly Sunshine Duration in Lahti: May Highlighted

The May sunshine duration represents the total number of hours Lahti experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec44h136h242h348h429h475h467h385h257h154h84h38h
Data source: Lahti May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Lahti During May

As May approaches in Lahti, Finland, the likelihood of enjoying sunny weather sees a notable shift. While the chances of sunshine in April stand at a robust 41%, they dip slightly to 29% in May. This trend reflects a transitional phase as spring gives way to summer; yet, it's still considerably brighter than the bleak winter months, with January's mere 3% chance of sun. By June, the sun makes its grand return, boasting a 51% likelihood, indicating that May's variability paves the way for the more consistently sunny days ahead. Overall, while not guaranteed, the potential for pleasantly sunny days in May captures the essence of spring's charm in Lahti.

Percentage of Sunny Days in May in Lahti

The chart illustrates the percentage of sunny days in Lahti throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Lahti experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec3%13%37%41%29%51%56%25%22%13%13%10%
Data source: Lahti May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Lahti in May

In Lahti, Finland, the transformation of daylight hours throughout the year is a captivating dance of light and shadow. As winter wanes into spring, daylight gradually extends from a mere 6 hours in January to a generous 14 hours by April. The month of May marks a delightful turning point, offering 17 hours of daylight, which sets the stage for the almost endless light of June, peaking at 19 hours. Following this luminous crescendo, the days begin to taper off once again, with July seeing 18 hours, and an eventual decline to 12 hours in September. By late autumn, daylight dwindles back to 7 hours in November and a mere 5 hours in December, culminating a seasonal cycle characterized by a vivid interplay between the bright, invigorating days of summer and the stark, serene calm of winter.

Average Daylight Hours in Lahti for May

The chart illustrates the variation in daylight duration in Lahti throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec6h 32m9h 1m11h 51m14h 44m17h 27m19h 4m18h 11m15h 39m12h 49m9h 58m7h 16m5h 40m
Data source: Lahti daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Lahti

In May, Lahti experiences a gentle breeze, with average wind speeds of 3.1 m/s (7 mph), maintaining the tranquil flow characteristic of early spring. This month's wind speed mirrors that of January and April, providing a sense of continuity as winter transitions to summer. Interestingly, while March sees a slight uptick to 3.8 m/s (8 mph), the winds begin to soften leading into the summer months. Following May, wind speeds dip further in June to 2.7 m/s (6 mph), signaling a shift towards the calmer conditions of summer. Overall, May stands as a bridge between the brisker winds of spring and the more languid breezes of the approaching summer, inviting both adventure and peaceful serenity in the Finnish landscape.

Average May Wind Speed in Lahti

The chart displays monthly wind speed patterns in Lahti, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.03.83.33.1 m/s2.72.83.63.34.13.63.4
Data source: Lahti May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Lahti Compares to Other Months

Weather in Lahti varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Lahti, focusing on differences in temperature, rainfall, humidity, and UV levels.

In comparing the weather between May and January, we see a stark contrast in temperatures and overall conditions. In May, temperatures vary from a chilly minimum of -3°C (27°F) to a pleasant average of 10°C (50°F), reaching highs of up to 28°C (83°F). This month also experiences a moderate level of precipitation, totaling 54 mm (2.1 inches) over about 10 days, accompanied by a humidity level of 75%.

In contrast, January presents a much colder climate, with temperatures plunging to a minimum of -25°C (-13°F), averaging at -4°C (25°F) and topping out around 7°C (46°F). The precipitation is slightly lower at 49 mm (1.9 inches) spread over approximately 11 days, and the humidity is significantly higher at 98%. For a more detailed look at January weather in Lahti, check out Lahti weather in January. Overall, May offers milder temperatures and less oppressive conditions compared to the harsh chill of January.

When comparing the weather in May and February, it's evident that May brings a significant increase in temperatures and a more pleasant atmosphere. In May, average temperatures range from a chilly 10°C (50°F) to a comfortable 28°C (83°F), while February experiences much colder conditions, with averages around -5°C (24°F) and a maximum of only 7°C (46°F). Although both months have a similar level of precipitation—54 mm (2.1 in) in May and 45 mm (1.8 in) in February—the humidity is notably higher in February at 96%, compared to May's 75%. The increased warmth and lower humidity in May make it a more inviting month, especially when compared to the harsh cold of February. For more detailed information, you can check Lahti weather in February.

May typically brings much milder temperatures compared to March, with highs reaching up to 28°C (83°F) and an average of 10°C (50°F), while March struggles with colder conditions, where temperatures peak at just 11°C (52°F) and often drop to as low as -25°C (-13°F). Precipitation levels are slightly higher in May at 54 mm (2.1 in) over 10 days, compared to March’s 45 mm (1.8 in) but with one more day of rain. Additionally, the humidity in May stands at a comfortable 75%, while March experiences a much higher humidity level at 93%. For more detailed March weather insights, you can visit Lahti weather in March.

May generally offers milder and more varied weather compared to April. The minimum temperature in May is notably warmer at -3°C (27°F) than April's -11°C (12°F), while the average temperature rises significantly from 3°C (38°F) in April to 10°C (50°F) in May. The maximum temperature can reach up to 28°C (83°F) in May, compared to 20°C (69°F) in April, indicating a more pleasant climate as spring progresses. Precipitation levels are slightly higher in May with 54 mm (2.1 in) over 10 days, compared to April's 48 mm (1.9 in) across 11 days; however, the humidity in May is lower at 75% compared to April's 87%. For more detailed information about April weather, visit Lahti weather in April.

In May, the weather in Lahti experiences a broader temperature range, with minimums dropping to -3°C (27°F) and maximums reaching up to 28°C (83°F). The average temperature hovers around 10°C (50°F), with precipitation totaling 54 mm (2.1 in) over about 10 days, and humidity levels at 75%. In contrast, June sees a significant rise in temperatures, where minimums are higher at 2°C (35°F) and maximums can soar to 31°C (87°F), resulting in an average temperature of 16°C (61°F). Precipitation also increases slightly to 63 mm (2.5 in) over 11 days, while humidity remains relatively stable at 74%. For more detailed insights on the weather during this month, check out Lahti weather in June.

May and July present quite a contrast in weather. In May, temperatures can dip as low as -3°C (27°F), but the average hovers around a mild 10°C (50°F), peaking at a comfortable 28°C (83°F). However, this month experiences a fair amount of precipitation, with about 54 mm (2.1 in) falling over 10 days, accompanied by a humidity level of 75%. In contrast, July sees warmer temperatures, with a minimum of 7°C (45°F) and an average of 17°C (64°F), reaching a maximum of 30°C (87°F). The month is also wetter, with 77 mm (3.0 in) of rain over approximately 12 days and a slightly higher humidity of 80%. To learn more about the specifics of July weather, you can visit Lahti weather in July.

In May, the weather is cool and variable, with temperatures ranging from a chilly -3°C (27°F) at night to a pleasant average of 10°C (50°F) during the day, peaking at 28°C (83°F). The month sees around 54 mm (2.1 in) of precipitation over approximately 10 days, accompanied by a humidity level of 75%. In contrast, August presents a warmer climate with temperatures starting at a mild 6°C (43°F) in the mornings, an average of 16°C (61°F), and highs reaching up to 31°C (87°F). However, it is slightly wetter, with 80 mm (3.2 in) of precipitation spread across about 13 days, and the humidity increases to 85%. For more specific insights into August's weather, you can check Lahti weather in August.

In May, the weather begins to warm up, with average temperatures reaching around 10°C (50°F) and highs that can climb to 28°C (83°F). However, nighttime temperatures can still drop to as low as -3°C (27°F), indicating a lingering chill. The month sees about 54 mm (2.1 in) of precipitation over approximately 10 days, and humidity levels average around 75%.

In contrast, September brings cooler conditions as summer wanes, with average temperatures around 11°C (52°F) and maximums peaking at 23°C (73°F). Nighttime temperatures dip slightly less dramatically, with a minimum of -1°C (30°F). Precipitation increases to 62 mm (2.5 in) across about 11 days, accompanied by higher humidity levels of 90%. For more detailed insights on September weather, check out Lahti weather in September.

May and October present distinct weather patterns, reflecting the transition between spring and autumn. In May, temperatures range from a brisk -3°C (27°F) at night to a warm 28°C (83°F) during the day, with an average of 10°C (50°F). This month experiences a moderate amount of precipitation, totaling 54 mm (2.1 in) spread over about 10 days, and humidity sits at 75%. In contrast, October sees cooler temperatures, with a minimum of -5°C (23°F) and a maximum of 18°C (64°F), averaging around 6°C (43°F). This month is wetter, receiving 78 mm (3.1 in) of precipitation over about 15 days, along with higher humidity at 94%. To learn more about the specific weather conditions you might expect, check out Lahti weather in October.

When comparing the weather in May and November, significant differences emerge. May experiences milder temperatures, ranging from a minimum of -3°C (27°F) to a maximum of 28°C (83°F), with an average of 10°C (50°F). In contrast, November is much colder, with temperatures dipping to a minimum of -10°C (14°F) and only reaching a maximum of 12°C (53°F), while the average is a chilly 2°C (36°F). Both months receive similar precipitation, around 54 mm (2.1 inches), but November sees a slightly higher frequency of rainfall, with precipitation on 11 days compared to May’s 10 days. Additionally, humidity levels are notably higher in November at 94%, compared to May's 75%, contributing to a more damp and chilly atmosphere. For more details on November weather, visit Lahti weather in November.

May and December present starkly contrasting weather conditions. In May, temperatures range from a mild minimum of -3°C (27°F) to a warm maximum of 28°C (83°F), with an average of 10°C (50°F). The month sees relatively moderate precipitation of 54 mm (2.1 in) over about 10 days and a humidity level of 75%. In contrast, December experiences much colder temperatures, with a minimum of -20°C (-4°F), an average of -2°C (28°F), and a maximum of only 5°C (42°F). The precipitation in December increases to 71 mm (2.8 in) but occurs over a longer span of 16 days, accompanied by high humidity at 96%. To learn more about the weather in December, you can check Lahti weather in December.

Compare Lahti's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Lahti

As May unfolds in Lahti, the weather begins to shift dramatically, emerging from the chill of winter into a more temperate climate. Daytime temperatures can soar up to 28°C (83°F), offering a stark contrast to the average of just 10°C (50°F) experienced earlier in the year. While occasional frosts are still possible, the warmth invites residents and visitors alike to embrace the beauty of spring. However, with an average of 10 rainy days and a humidity level of around 75%, it’s wise to be prepared for the occasional shower amidst blossoming landscapes. For more details on what to expect throughout the year, check out the full Lahti Climate guide.