Last updated: August 21, 2025
September in Lappeenranta, Finland presents a delightful transition into autumn, with temperatures ranging from a pleasant maximum of 23°C (73°F) to a cool minimum of 0°C (32°F). The month features an average temperature of 11°C (53°F), making it an inviting time for outdoor activities. Visitors can expect around 67 mm (2.6 in) of precipitation spread over 13 days, contributing to the landscape’s lush beauty. With humidity levels soaring at an average of 90%, the air carries a refreshing crispness, perfect for enjoying the stunning views and changing foliage of this Nordic gem.
As summer transitions into autumn, September in Lappeenranta, Finland, brings a refreshing change in temperatures that marks the gradual cooling of the year. With minimum temperatures hovering around 0°C (32°F) and averages reaching 11°C (53°F), the month serves as a gentle reminder of the colder months ahead. While daytime highs can still peak at a pleasant 23°C (73°F), the crisp mornings and cooler evenings create a perfect backdrop for enjoying the last remnants of outdoors before winter settles in. This shift not only sets the stage for vibrant fall foliage but also invites local residents and visitors alike to savor the beauty of Lappeenranta as it adjusts to a new season.
In September, Lappeenranta experiences a notable shift in precipitation patterns, with 67 mm (2.6 in) of rain over 13 days, reflecting a transitional phase into the wetter autumn months. Following the summer peak in August, where rainfall reached 88 mm (3.4 in), September sees a decrease yet remains significantly moist, indicating the lingering influence of the warm season. This month often serves as a buffer, bridging the gap between the lushness of summer and the upcoming chill, as evidenced by the rise in precipitation that typically continues into October's 76 mm (3.0 in). Such trends illustrate the region's dynamic climate, where each month builds upon the previous, painting a vivid picture of Lappeenranta's vibrant weather patterns.
September in Lappeenranta, Finland, experiences a notable increase in humidity, reaching 90%. This month's humidity stands out as a transitional point, following the warmer summer months of July and August, which see levels of 82% and 84% respectively. As autumn approaches, the humidity begins to climb again, reminiscent of the high figures from the winter months—January peaks at a staggering 98%. Overall, September marks a shift from the relative dryness of summer to the thicker, more moisture-laden air characteristic of the upcoming fall and winter, creating a distinct atmospheric change for residents and visitors alike.
As September arrives in Lappeenranta, Finland, the UV Index takes a noticeable dip, settling at a moderate level of 3. This marks a shift from the high levels of summer, where values peaked at 7 in June and July, reflecting a time of heightened sun exposure. With a burn time of 30 minutes, it’s essential to remain mindful of sun protection during outdoor activities this month. As the days become shorter and cooler, the overall trend shows a gradual decline in UV intensity, signaling the approach of autumn. To learn more about Lappeenranta's UV Index throughout the year, visit Lappeenranta UV Index.
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September in Lappeenranta, Finland, ushers in a transition from the sun-drenched heights of summer to the mellow tones of autumn, with 270 hours of sunshine illuminating the month. This substantial sunlight is indicative of the broader trend observed throughout the year, where winter months struggle with only 31 hours in January and 24 hours in December. As the seasons shift, sunshine peaks in the summer, reaching a peak of 479 hours in June, and begins to taper off in September compared to the previous months like May and July. This gradual decline in sunlight hours hints at the approaching chill, yet September still holds onto the last vestiges of summer warmth, making it a beautiful time to reflect on the vibrant days gone by and prepare for the crisp days ahead.
In Lappeenranta, Finland, the likelihood of sunny weather in September begins to wane as summer transitions to autumn, with a 21% chance of sunshine. While this percentage is an improvement over the colder months, it falls short compared to the peak summer months of June and July, which boast a robust 56% chance of sun. As the sunny days of August fade, September reveals its more temperate climate, marking a noticeable reduction in sunny spells. This trend is mirrored in the cooler months that follow, where chances of sunshine continue to diminish, highlighting September as a transitional time in the region's weather pattern.
As September arrives in Lappeenranta, Finland, the days begin to gradually shorten, offering about 12 hours of daylight—a noticeable decline from the sun-drenched peak of 19 hours in June. This month signals a transition from the vibrant length of summer days; while still basking in a decent amount of light, the length of daylight is now shorter than in the preceding summer. By October, daylight drops further to 9 hours, emphasizing the shift towards winter. Overall, September captures the essence of a changing season, as the landscape prepares for the cozy ambiance of autumn, blending the lingering warmth of summer with the crispness of the upcoming months.
As September breezes in Lappeenranta, Finland, the wind picks up slightly to an average speed of 3.5 m/s (8 mph), marking a subtle yet noticeable transition from the summer lull. This gentle increase follows August's more robust gusts, where winds reached 3.8 m/s (9 mph). While the early months of the year showcased a steadier, calmer atmosphere with averages below 4 m/s—particularly in June and July when wind speeds dipped to 2.9 m/s (6 mph)—September signals the approach of autumn as conditions begin to shift. The trend continues upward in October and November, where winds become increasingly vigorous, anticipating the cold months ahead. Overall, September serves as a delicate bridge between the light breezes of summer and the invigorating winds of fall.
Weather in Lappeenranta varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Lappeenranta, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present starkly contrasting weather patterns. In September, temperatures range from a brisk 0°C (32°F) at night to a pleasant maximum of 23°C (73°F) during the day, with an average of 11°C (53°F). The month experiences decent rainfall of 67 mm (2.6 in) over 13 days, and the humidity can feel quite high at 90%. In contrast, January is much colder, with temperatures plummeting to a minimum of -25°C (-12°F) and only reaching a maximum of 7°C (45°F), averaging around -4°C (24°F). This winter month sees less precipitation at 48 mm (1.9 in) over 11 days, but the humidity is slightly higher at 98%. For more details on January's weather, check out Lappeenranta weather in January.
September and February display markedly different weather patterns. In September, temperatures range from a minimum of 0°C (32°F) to a maximum of 23°C (73°F), with an average of 11°C (53°F). The month sees around 67 mm (2.6 in) of precipitation over 13 days, accompanied by a humidity level of 90%. In contrast, February is characterized by much colder conditions, with temperatures plummeting to a minimum of -28°C (-18°F) and averaging -5°C (23°F), peaking at just 6°C (43°F). It experiences slightly less precipitation, totaling 54 mm (2.1 in) across 11 days, but with a higher humidity of 96%. For more details on February weather, you can visit Lappeenranta weather in February.
When comparing the weather of September and March, notable differences emerge. September generally experiences a milder climate with temperatures ranging from a low of 0°C (32°F) to a pleasant maximum of 23°C (73°F) and an average of 11°C (53°F). It sees about 67 mm (2.6 in) of precipitation over 13 days, accompanied by a high humidity level of 90%. In contrast, March presents much colder conditions, with temperatures plummeting to a minimum of -24°C (-12°F) and an average of -2°C (29°F), reaching a maximum of only 11°C (51°F). The month witnesses a lower total precipitation of 48 mm (1.9 in) but maintains a similar frequency of precipitation over 13 days, with humidity slightly higher at 93%. For more details on March weather specifics, check out Lappeenranta weather in March.
When comparing the weather in September and April, we see distinct differences in temperature and precipitation patterns. In September, temperatures range from a chilly 0°C (32°F) at night to a pleasant high of 23°C (73°F) during the day, averaging around 11°C (53°F). This month experiences more rainfall, with 67 mm (2.6 in) of precipitation over 13 days and a humidity level of 90%. In contrast, April presents colder conditions, with nighttime lows dropping to -14°C (6°F) and daytime highs reaching 20°C (68°F), resulting in an average temperature of 3°C (38°F). Precipitation is lower at 44 mm (1.7 in) over 12 days, accompanied by slightly less humidity at 88%. For more details about the weather in April, visit Lappeenranta weather in April.
When comparing the weather in September to that of May, notable differences emerge. September typically sees a minimum temperature of 0°C (32°F) and an average of 11°C (53°F), with a maximum of 23°C (73°F). The month experiences about 67 mm (2.6 in) of precipitation over 13 days, contributing to a high humidity level of 90%. In contrast, May has a slightly lower minimum temperature of -4°C (26°F) but a higher maximum temperature of 28°C (83°F), with an average of 10°C (50°F). May also experiences less precipitation at 51 mm (2.0 in) over 10 days, resulting in a lower humidity level of 77%. For more detailed weather information, you can check Lappeenranta weather in May.
When comparing the weather in September and June, notable differences emerge. September experiences cooler temperatures, with a minimum of 0°C (32°F) and an average of 11°C (53°F), while June boasts warmer conditions, featuring a minimum of 2°C (36°F) and an average of 16°C (62°F). Moreover, June can reach maximum temperatures of 31°C (89°F), significantly higher than September's peak of 23°C (73°F). In terms of precipitation, September sees 67 mm (2.6 in) over 13 days, compared to June's 52 mm (2.1 in) over 10 days, with September also exhibiting higher humidity levels at 90% versus June's 75%. For more detailed insights into June weather, check out Lappeenranta weather in June.
When comparing the weather in September and July, significant differences emerge. September experiences cooler temperatures, with a minimum of 0°C (32°F) and an average of 11°C (53°F), contrasting sharply with July's milder conditions, where temperatures range from a minimum of 7°C (46°F) to an average of 18°C (64°F). July also boasts higher maximum temperatures, reaching up to 32°C (89°F), while September peaks at only 23°C (73°F). Both months see a similar number of precipitation days—13—yet September has a slightly lower total rainfall of 67 mm (2.6 in) compared to July's 74 mm (2.9 in). Additionally, September is more humid at 90%, while July's humidity sits at 82%. For more details on the climate during July, you can check Lappeenranta weather in July.
In August, temperatures ranged from a minimum of 7°C (45°F) to a maximum of 30°C (86°F), resulting in an average of 16°C (61°F). The month experienced higher precipitation, totaling 88 mm (3.4 in) over 15 days, along with a humidity level of 84%. Conversely, September saw a significant drop in temperatures, with a minimum of 0°C (32°F) and a maximum reaching 23°C (73°F), while the average temperature was 11°C (53°F). The precipitation in September was 67 mm (2.6 in) across 13 rainy days, but the humidity increased to 90%. For a more detailed look at August weather, visit Lappeenranta weather in August.
September and October present a noticeable shift in weather patterns. September typically enjoys milder temperatures with a minimum of 0°C (32°F) and an average of 11°C (53°F), reaching up to 23°C (73°F) on warmer days, while October sees a drop with temperatures ranging from a minimum of -4°C (25°F) to an average of 6°C (44°F), peaking at 18°C (64°F). Precipitation increases slightly from 67 mm (2.6 in) over 13 days in September to 76 mm (3.0 in) across 14 days in October, contributing to a rise in humidity levels from 90% to 93%. This transition marks a shift towards cooler and wetter conditions, making it a notable change as autumn progresses. For more detailed information, you can refer to Lappeenranta weather in October.
In September, the weather typically features a minimum temperature of 0°C (32°F), an average of 11°C (53°F), and a maximum of 23°C (73°F), with precipitation of 67 mm (2.6 in) spread over 13 days and humidity levels around 90%. In contrast, November ushers in much colder temperatures, with a minimum of -8°C (17°F), an average of 2°C (36°F), and a maximum reaching only 11°C (52°F). Precipitation during this month dips slightly to 50 mm (2.0 in) over 11 days, while humidity rises to 93%. For more detailed information on November weather, you can check Lappeenranta weather in November.
September and December exhibit stark contrasts in weather conditions. In September, temperatures range from a chilly 0°C (32°F) at night to a pleasant 23°C (73°F) during the day, with an average of 11°C (53°F). The month sees 67 mm (2.6 in) of precipitation over 13 days, and humidity levels hover around 90%. By December, the scene shifts dramatically; temperatures drop significantly, with lows reaching -20°C (-4°F) and highs only reaching 5°C (42°F), averaging -3°C (27°F). Although December has slightly more precipitation at 74 mm (2.9 in) spread over 16 days, the increased humidity at 95% contributes to a much colder feel. For more detailed insights, you can check Lappeenranta weather in December.
As September unfolds in Lappeenranta, the weather presents a striking transition from the warmth of summer to the cooler embrace of autumn. With an average temperature around 11°C, this month is notably cooler compared to the previous months, reflecting the changing season's approach. The likelihood of rain increases, with nearly half the days seeing precipitation, contributing to a hazy, humid atmosphere with humidity levels soaring to 90%. This month serves as a beautiful bridge between the vibrant greenery of summer and the crispness of fall, inviting both locals and visitors to enjoy the rich tapestry of nature. For a deeper understanding of what to expect throughout the year, explore more about the city's climate at Lappeenranta Climate.