September Weather in Viimsi, Estonia

Last updated: August 21, 2025

In September, Viimsi, Estonia, experiences a delightful transition into fall, with temperatures ranging from a maximum of 24°C (75°F) to a minimum of 3°C (37°F), averaging around 13°C (55°F). This month is characterized by an 87% humidity level and approximately 78 mm (3.1 in) of rainfall spread over 15 days, creating a refreshing yet somewhat damp atmosphere. As the leaves begin to turn, visitors can enjoy the vibrant landscapes that accompany this crisp and invigorating time of year. Whether you're exploring the scenic coastlines or enjoying local festivals, September in Viimsi offers a unique blend of warmth and coolness, perfect for outdoor adventures.

September Temperature in Viimsi

In Viimsi, Estonia, September marks a gentle transition into autumn, characterized by mild temperatures that offer a pleasant retreat from the summer heat. With nighttime lows averaging around 3°C (37°F) and daytime highs reaching up to 24°C (75°F), September provides a comfortable climate for outdoor activities. The month sees an average temperature of 13°C (55°F), a notable drop from the warmer summer months but still inviting for locals and visitors alike. As the vibrant hues of autumn begin to paint the landscape, this month serves as a bridge between the warm ebb of summer and the crisp onset of fall, making it a delightful time to experience the natural beauty of the region.

September Weather in Viimsi: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Viimsi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Viimsi, September 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).
JanFebMarAprMayJunJulAugSepOctNovDec302833404960646255474032
Data source: Temperature data for Viimsi 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.

September Precipitation in Viimsi

In September, Viimsi, Estonia experiences a notable increase in precipitation, receiving 78 mm (3.1 in) of rain over 15 days. This marks a shift from the drier summer months, where August peaked at 102 mm. As autumn sets in, rainfall tends to become more frequent, signaling a gradual transition to wetter conditions ahead. The relatively high number of precipitation days indicates that while the rain is persistent, the intensity may vary, contributing to a refreshing and crisp atmosphere that characterizes this time of year. Overall, September serves as a bridge between the lush summer rains and the heavier downpours expected in October, which often averages around 100 mm (3.9 in).

September Precipitation Trends in Viimsi

The chart displays monthly precipitation patterns in Viimsi, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Viimsi, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec44484742545568102781005860
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Viimsi

In Viimsi, Estonia, the month of September witnesses a notable shift in humidity levels, hovering at 87%. This marks an increase from the warmer, late summer months where humidity settled around 83% in August. As the summer heat gradually fades, a subtle rise in moisture can be felt, reminiscent of the early autumn days. This trend reflects the overall pattern in Viimsi, where humidity peaks during the winter months, reaching up to 92% in January, and stabilizes steadily throughout the fall. The transition into September not only signals the arrival of cooler weather but also a return to a more humid atmosphere, intertwining with the scenic charm of Estonia’s changing seasons.

September Average Humidity in Viimsi

This chart illustrates the average monthly humidity levels in Viimsi, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Viimsi is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%91%90%87%76%80%80%83%87%90%91%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Viimsi

As summer fades into autumn, September in Viimsi, Estonia sees a moderate UV Index of 4, indicating a still significant, yet manageable level of sun exposure. This marks a slight decline from the high levels experienced in the peak summer months of June and July, when the UV Index reached 7. As the days shorten and the sun's rays become less intense, locals and visitors can feel secure with a burn time of 30 minutes, allowing for outdoor activities with a cautious approach to sun safety. With autumn on the horizon, it's a great time to enjoy the outdoors while keeping in mind the importance of protection against UV rays. For more details on sun safety, visit Viimsi UV Index.

Maximum UV Index Levels in Viimsi for September

The chart shows the monthly maximum UV Index (UVI) for Viimsi in September, 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 September, the maximum UV index in Viimsi typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113457754211
Data source: Viimsi September 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.

September Sunshine in Viimsi

In Viimsi, Estonia, September marks a graceful transition into autumn, characterized by a remarkable abundance of sunshine with 303 hours of sunlight. This pleasant month reflects a significant decline compared to the sun-drenched summer, where June and July basked in nearly 500 hours each. However, September still retains more light than the darker winter months ahead, eclipsing October's 206 hours and offering a warm farewell to the vibrant days of summer. This pattern illustrates how the sun's embrace gradually wanes, inviting cozy evenings while still cherishing the bright remnants of the past season. As daylight seeks its retreat, the crisp air heralds the arrival of an enchanting fall, making September a perfect time to enjoy the lingering warmth before winter's chill sets in.

Monthly Sunshine Duration in Viimsi: September Highlighted

The September sunshine duration represents the total number of hours Viimsi experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec61h157h268h367h452h488h481h408h303h206h121h64h
Data source: Viimsi September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Viimsi During September

In Viimsi, Estonia, the likelihood of sunny weather experiences significant fluctuations throughout the year, peaking in the summer months. July and June boast the highest chances of sunshine, with probabilities soaring to 58% and 54% respectively, providing perfect opportunities for outdoor activities. As summer wanes, August offers a still reasonable 33%, but by September, the chance of sunny days dwindles to 28%. This trend reflects the gradual transition into autumn, where sunny skies become increasingly scarce, marking a shift towards cooler, cloudier days ahead. As the year progresses, the likelihood of sunshine diminishes, with only 22% anticipated by October, hinting that anyone visiting Viimsi in September should embrace the sunshine while it lasts!

Percentage of Sunny Days in September in Viimsi

The chart illustrates the percentage of sunny days in Viimsi throughout the year, with September 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 Viimsi experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec5%15%35%43%33%55%58%33%28%22%21%13%
Data source: Viimsi September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Viimsi in September

In September, Viimsi, Estonia experiences a balanced transition from the long days of summer to the shorter daylight hours of autumn. With approximately 12 hours of daylight, this month marks a noticeable decrease from August's 15 hours, yet still offers ample natural light for outdoor activities. As the days gradually shorten, the warmth of the lingering summer sun begins to fade, paving the way for the crispness of fall. This trend continues into October, where daylight further dwindles to around 10 hours, reminding residents to savor the last golden rays of September. The gradual shift in daylight not only alters the rhythm of daily life but also enhances the beautiful autumnal transformations in Viimsi’s landscapes.

Average Daylight Hours in Viimsi for September

The chart illustrates the variation in daylight duration in Viimsi throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec6h 55m9h 12m11h 51m14h 34m17h 4m18h 31m17h 44m15h 25m12h 46m10h 6m7h 35m6h 8m
Data source: Viimsi daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Viimsi

As summer transitions to autumn, September in Viimsi, Estonia, showcases a steady yet invigorating wind, averaging 5.0 m/s (11 mph). This consistent breeze mirrors the preceding month's wind patterns, maintaining a pleasant balance in the air before the stronger gusts of October emerge. Comparing September to earlier months, we observe a gentle resurgence in wind speed from the quieter summer, which recorded its lowest average in June at 3.3 m/s (7 mph). As nature prepares for the cooler months ahead, this month’s winds serve as a refreshing reminder of the change in seasons, setting the stage for the brisker conditions that lie just around the corner.

Average September Wind Speed in Viimsi

The chart displays monthly wind speed patterns in Viimsi, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.54.45.54.94.23.33.95.05.0 m/s6.15.65.0
Data source: Viimsi September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Viimsi Compares to Other Months

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

In September, the weather is generally mild, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 24°C (75°F), averaging around 13°C (55°F). With 78 mm (3.1 in) of precipitation spread over 15 days and a humidity level of 87%, the month tends to feel quite damp. In contrast, January experiences much colder conditions, with temperatures plummeting to a minimum of -16°C (3°F) and a maximum of 8°C (46°F), averaging -1°C (30°F). Despite lower precipitation of 44 mm (1.7 in) across 11 days, the humidity increases to 92%, creating a distinctly chilly atmosphere. For more specific details about the conditions, you can visit Viimsi weather in January.

In September, temperatures typically range from a mild 3°C (37°F) at night to a pleasant 24°C (75°F) during the day, with an average temperature of 13°C (55°F). This month experiences relatively high humidity at 87% and averages 78 mm (3.1 in) of precipitation over about 15 days. In contrast, February presents a starkly different climate, with frigid minimum temperatures plunging to -21°C (-6°F) and a maximum of only 7°C (44°F), bringing the average to -2°C (28°F). Despite slightly lower precipitation of 48 mm (1.9 in) spread over 11 days, February’s humidity is notably high at 91%. For more detailed information, you can check Viimsi weather in February.

September and March showcase contrasting weather patterns, reflective of their positions within the seasonal cycle. September typically enjoys milder temperatures, ranging from a minimum of 3°C (37°F) to a maximum of 24°C (75°F), with an average of 13°C (55°F). The month experiences a fair amount of rainfall, with 78 mm (3.1 in) spread over 15 days and humidity levels at 87%. In contrast, March is much colder, with temperatures dipping to a minimum of -18°C (0°F) and only reaching a maximum of 10°C (51°F), averaging around 0°C (33°F). March sees less precipitation at 47 mm (1.9 in) across 13 days, but the humidity is slightly higher at 90%. For a more detailed look at the weather patterns during March, you can refer to Viimsi weather in March.

In comparing the weather of September and April, we can see some notable differences. September tends to be warmer, with average temperatures ranging from a chilly 3°C (37°F) at night to a pleasant 24°C (75°F) during the day, while April’s temperatures are cooler, peaking at a maximum of 18°C (65°F) and dropping as low as -8°C (18°F). Additionally, September experiences more rainfall, totaling 78 mm (3.1 in) over about 15 days, compared to April’s 41 mm (1.6 in) spread over 10 days. Despite the similar 87% humidity in both months, the overall feel of September leans towards a mild and comfortable transition into autumn, whereas April often carries the crispness of early spring. For a more detailed look at April's weather, you can visit Viimsi weather in April.

When comparing weather conditions in September and May, notable differences emerge. September typically sees a minimum temperature of 3°C (37°F) and an average of 13°C (55°F), while May holds a cooler minimum of -2°C (29°F) and an average of 10°C (50°F). Both months can reach a maximum of 24°C (75°F), but September experiences more rainfall, totaling 78 mm (3.1 in) across 15 days compared to May's 54 mm (2.1 in) over just 9 days. Additionally, September has a higher humidity level at 87%, while May maintains a slightly lower humidity of 76%. For a detailed look at the specifics of May weather, you can check Viimsi weather in May.

In September, temperatures begin to cool down, with a minimum of 3°C (37°F) and an average of 13°C (55°F), while reaching a maximum of 24°C (75°F). This month is characterized by higher rainfall, with 78 mm (3.1 in) of precipitation over approximately 15 days and a humidity level of 87%. In contrast, June boasts milder conditions, with minimum temperatures of 5°C (41°F) and an average of 16°C (60°F), peaking at 30°C (87°F). Precipitation is lower in June at 55 mm (2.2 in), occurring over just 9 days and accompanied by a humidity level of 80%. For more detailed information, see Viimsi weather in June.

In comparing the weather between July and September, we see notable differences in temperature and precipitation. July tends to be warmer, featuring a minimum temperature of 9°C (48°F) and an average high of 30°C (86°F), while September cools off with a minimum of 3°C (37°F) and an average high of 24°C (75°F). Additionally, July experiences less rainfall, with 68 mm (2.7 in) over 11 days compared to September's 78 mm (3.1 in) over 15 days. Humidity levels are also slightly higher in September at 87% compared to July's 80%. For more detailed insights about July weather, visit Viimsi weather in July.

In comparing the weather of September and August, September tends to be cooler and slightly wetter. The average temperature drops from 17°C (63°F) in August to 13°C (55°F) in September, with maximum temperatures reaching only 24°C (75°F) compared to August’s higher peak of 29°C (84°F). Additionally, September experiences a bit more precipitation, totaling 78 mm (3.1 in) over 15 days, while August sees 102 mm (4.0 in) over the same number of days. Humidity levels are relatively comparable, with September averaging 87% versus August's 83%. For a detailed look at the weather in August, you can check out Viimsi weather in August.

In comparing the weather between September and October, there's a noticeable drop in temperature and an increase in precipitation. September enjoys milder temperatures, ranging from a minimum of 3°C (37°F) to a maximum of 24°C (75°F), while October sees the mercury dip significantly, with temperatures ranging from a low of -2°C (29°F) to a high of 17°C (64°F). Additionally, October experiences more rainfall, accumulating 100 mm (3.9 in) across 17 days, compared to September's 78 mm (3.1 in) over 15 days. Humidity also rises slightly, peaking at 90% in October compared to 87% in September. For a more detailed look, you can check Viimsi weather in October.

September and November showcase a significant transition in weather patterns. In September, temperatures range from a mild 3°C (37°F) to a pleasant 24°C (75°F), with an average of 13°C (55°F), making it a transitional month with more comfortable days. With 78 mm of precipitation over 15 days, the humidity remains high at 87%, contributing to a damp atmosphere. In contrast, November brings a notable chill, with temperatures dipping to a minimum of -5°C (24°F) and an average of just 4°C (40°F). Though November sees a decrease in total precipitation at 58 mm over 13 days, the humidity rises to 91%, creating a cooler and more moist environment. For more insights on November weather, you can check this link: Viimsi weather in November.

In September, the weather is generally mild, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 24°C (75°F) and an average of 13°C (55°F). The month experiences significant rainfall, totaling 78 mm (3.1 in) over 15 days, and the humidity is relatively high at 87%. In contrast, December brings much colder temperatures, with lows plunging to -17°C (1°F) and an average temperature of 0°C (32°F), peaking at 7°C (46°F). Although December receives a bit less precipitation at 60 mm (2.4 in) spread over 16 days, the humidity rises slightly to 90%. For detailed insights on December weather, check Viimsi weather in December.

Compare Viimsi's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Viimsi

As September unfolds in Viimsi, the weather showcases a distinctive transition from the warmth of summer to the crispness of autumn. While early September might still flirt with pleasant temperatures, the chill of approaching winter becomes undeniable, with nights dipping significantly. Vibrant colors emerge as the landscape changes, and the increase in rainfall and humidity adds a refreshing touch to the air. Unlike the drier months of summer, September sees more days of precipitation, keeping the natural surroundings lush and vibrant. Experience the unique charm of this month and learn more about the overall weather patterns in Viimsi by visiting Viimsi Climate.