September Weather in Hammarby, Sweden

Last updated: August 27, 2025

September in Hammarby, Sweden, offers a vibrant transition from summer to autumn, characterized by a maximum temperature of 24°C (75°F) and an average of 11°C (53°F). As the month unfolds, temperatures can dip to a chilly minimum of -1°C (31°F), emphasizing the seasonal shift. Rainfall is moderate, with 53 mm (2.1 in) accumulated over 9 days, contributing to the lush landscapes of the region. With humidity levels at a notable 87%, the air is rich and crisp, perfect for enjoying the scenic beauty of Hammarby during this enchanting time of year.

September Temperature in Hammarby

In September, Hammarby, Sweden begins to transition from the warmth of summer to the crispness of autumn. The temperatures start to cool, with minimums dipping to -1°C (31°F), while daily averages hover around a comfortable 11°C (53°F). This month also boasts a pleasant maximum of 24°C (75°F), perfect for enjoying the last of the outdoor activities before winter sets in. Compared to the preceding months, September offers a delightful balance—a gentle reminder of the approaching fall, with the scenery transforming into vibrant shades of orange and red. As daylight wanes, the crisp air invites both locals and visitors to experience the beauty of Hammarby’s natural landscapes.

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

The chart illustrates September temperature patterns in Hammarby, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hammarby, 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).
JanFebMarAprMayJunJulAugSepOctNovDec282833405061636053443630
Data source: Temperature data for Hammarby 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 Hammarby

September in Hammarby, Sweden, brings a moderate 53 mm (2.1 in) of precipitation over nine days, continuing the trend of increasing rainfall that began in the summer months. Following the rainier August, where the area recorded an impressive 90 mm (3.5 in), September experiences a slight dip, yet maintains a balance that signifies the transition into autumn. The relatively consistent rainfall patterns indicate a shift from the drier months of early spring, with the onset of cooler weather and the upcoming October poised to deliver even heavier precipitation at 88 mm (3.5 in). As the days grow shorter and the temperature drops, the regularity of rainfall serves to nourish the lush landscapes, making September a pivotal month in the seasonal cycle.

September Precipitation Trends in Hammarby

The chart displays monthly precipitation patterns in Hammarby, 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 Hammarby, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec363639295770709053884956
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hammarby

In Hammarby, Sweden, September brings a noticeable increase in humidity, with levels rising to 87%. This shift marks a transition from the relatively drier conditions of summer, where July and June hover around 73%, to the more humid fall months. As summer fades into autumn, the air becomes thicker with moisture, preparing for the impending chill of October, which sees humidity levels jump back up to 92%. Overall, September acts as a bridge, linking the warm, drier months of the year to the dampness that characterizes the later autumn and winter seasons, reminding residents that change is on the horizon.

September Average Humidity in Hammarby

This chart illustrates the average monthly humidity levels in Hammarby, 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 Hammarby is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec96%93%91%84%74%73%73%78%87%92%94%94%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hammarby

As summer fades into fall, September in Hammarby, Sweden sees a moderate UV Index rating of 4, reflecting a gentle decline from the higher values of the peak months. This drop signifies a transition from the intense sun exposure of July and August, which both held a UV Index of 7, to more manageable levels, where the recommended burn time is approximately 30 minutes. With an exposure category still classified as moderate, it's essential for residents and visitors to remain mindful of sun safety as they enjoy the lingering warmth. For comprehensive UV Index details throughout the year, visit Hammarby UV Index.

Maximum UV Index Levels in Hammarby for September

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

As September arrives in Hammarby, Sweden, the days begin to shorten, bringing a significant reduction in sunshine hours compared to the vibrant summer months. After basking in an impressive 475 hours of sunlight in July, residents transition to a more subdued 278 hours in September. This trend of diminishing daylight persists into the autumn, as October's sun gives way to just 196 hours. Despite the decline, September holds onto the final glimpses of summer warmth, allowing locals to savor the beautiful, crisp days before winter settles in. The gradual shift from the bright, long days of summer to the gentle embrace of autumn creates a unique atmosphere, inviting reflection and appreciation for the changing seasons.

Monthly Sunshine Duration in Hammarby: September Highlighted

The September sunshine duration represents the total number of hours Hammarby 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.
JanFebMarAprMayJunJulAugSepOctNovDec70h165h264h368h420h465h475h392h278h196h113h67h
Data source: Hammarby September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hammarby During September

In Hammarby, Sweden, the likelihood of sunny weather in September shows a notable decline, with only a 25% chance of sunshine. This marks a dip from the summer peak in July, which boasts a 50% chance, indicating a gradual transition into the cooler months. Following the vibrant, sun-drenched days of July and August, September's sunshine chance aligns more closely with the overcast tendencies of October and December, both also sitting at 25%. This trend underscores the fleeting nature of summer warmth, reminding residents and visitors alike to enjoy the remaining sunny days before autumn settles in.

Percentage of Sunny Days in September in Hammarby

The chart illustrates the percentage of sunny days in Hammarby 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 Hammarby experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec15%31%36%47%27%41%50%32%25%25%28%25%
Data source: Hammarby September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hammarby in September

As summer slowly surrenders to autumn in Hammarby, Sweden, September brings a gentle decline in daylight, offering about 12 hours of daylight. This month marks a pivotal transition from the sun-drenched days of June and July, where daylight peaks at 18 hours, to the crisp, shorter days of autumn. The gradual tapering from 15 hours in August to 10 hours in October highlights the shortening days as the sun begins its retreat. As the vibrant hues of summer fade, September serves as a beautiful reminder of nature’s rhythms, inviting residents and visitors alike to savor the softer light and cooler temperatures before winter descends.

Average Daylight Hours in Hammarby for September

The chart illustrates the variation in daylight duration in Hammarby throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec6h 38m9h 4m11h 51m14h 41m17h 21m18h 55m18h 4m15h 35m12h 48m10h7h 21m5h 48m
Data source: Hammarby daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hammarby

As the summer winds down in Hammarby, Sweden, September greets residents with a gentle breeze, averaging 3.1 m/s (7 mph). This slight dip from the more robust currents of late summer (3.2 m/s in August) marks a transitional phase, reminiscent of the quiet shift towards autumn. Throughout the year, wind speeds dance within a modest range, with January to April consistently showcasing winds hovering around 3.1 to 3.6 m/s, while summer months typically witness a calming effect, with speeds descending to about 2.7 m/s. However, as the leaves begin to change, October ushers in a noticeable increase at 4.1 m/s (9 mph), hinting at the upcoming seasonal gusts. Overall, September's winds evoke a serene yet refreshing atmosphere, perfectly embodying the essence of the early autumn transition.

Average September Wind Speed in Hammarby

The chart displays monthly wind speed patterns in Hammarby, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.53.63.52.92.72.73.23.1 m/s4.13.33.2
Data source: Hammarby September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Hammarby Compares to Other Months

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

In September, the weather tends to be mild and pleasant, with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 24°C (75°F) and an average of 11°C (53°F). The month experiences about 53 mm (2.1 in) of precipitation over approximately 9 days, while humidity levels hover at 87%. In contrast, January is significantly colder, with temperatures plummeting to a minimum of -22°C (-8°F) and peaking at just 9°C (49°F), averaging around -2°C (28°F). Despite having slightly less precipitation at 36 mm (1.4 in) across 8 days, January's humidity is notably higher at 96%. For those interested in a more detailed look at January weather, check out Hammarby weather in January.

September and February present strikingly different weather conditions. In September, temperatures range from a chilly 1°C (31°F) at night to a warm 24°C (75°F) during the day, with an average of 11°C (53°F). The month experiences moderate precipitation of 53 mm (2.1 in) over about 9 days, while humidity hovers around 87%, creating a crisp but pleasant atmosphere. In contrast, February is significantly colder, with temperatures plummeting to a minimum of -17°C (1°F) and peaking at only 9°C (48°F), resulting in an average of -2°C (28°F). Although February has less precipitation, at 36 mm (1.4 in) over 8 days, the humidity is slightly higher at 93%, contributing to a more biting chill. For more specific details on February weather, check out Hammarby weather in February.

In comparing the weather between September and March, September typically enjoys milder temperatures, ranging from a low of -1°C (31°F) to a high of 24°C (75°F), with an average of 11°C (53°F). The month sees an average of 53 mm (2.1 in) of precipitation over about 9 days, coupled with a relatively high humidity of 87%. In contrast, March experiences more extreme conditions, with temperatures dipping as low as -20°C (-3°F) and reaching a maximum of 18°C (64°F), resulting in an average of 0°C (33°F). Precipitation is somewhat lower at 39 mm (1.5 in), spread over 7 days, and the humidity is slightly higher at 91%. For a more detailed look at March weather specifics, check out Hammarby weather in March.

In September, the weather tends to be milder with average temperatures reaching around 11°C (53°F), and maximums hitting 24°C (75°F), while enjoying relatively high humidity at 87%. Precipitation is also more significant during this month, with about 53 mm (2.1 in) spread over 9 days. In contrast, April experiences cooler temperatures, averaging around 4°C (40°F) and peaking at a maximum of 21°C (70°F), but with lower humidity at 84%. Precipitation is less frequent in April, with about 29 mm (1.1 in) over 7 days. For a more detailed look at what to expect, check out Hammarby weather in April.

In comparing the weather of September and May, we observe notable differences in temperature and humidity. September features a milder temperature range, with minimums around -1°C (31°F) and maximums reaching 24°C (75°F), resulting in an average of 11°C (53°F). In contrast, May starts cooler, with minimum temperatures dipping to -5°C (24°F) but can rise to a more significant maximum of 28°C (83°F), producing an average temperature of 10°C (51°F). Both months experience substantial precipitation, with September receiving 53 mm (2.1 in) over 9 days and May slightly higher at 57 mm (2.3 in) over 11 days. Humidity levels are higher in September at 87%, compared to a lower 74% in May, giving the latter month a drier feel. For more specific details, you can check Hammarby weather in May.

When comparing the weather in September and June, it's clear that both months offer distinct conditions. September features a wider temperature range with minimums dropping to -1°C (31°F) and pleasant maximums reaching up to 24°C (75°F), with an average of 11°C (53°F). In contrast, June tends to be warmer, with minimum temperatures starting at 4°C (39°F), an average of 16°C (61°F), and maximums soaring up to 31°C (88°F). Precipitation is also notable in both months, with September receiving around 53 mm (2.1 in) over 9 days, while June experiences a slightly higher precipitation total of 70 mm (2.7 in) over 10 days. Humidity levels are higher in September at 87%, compared to June's 73%. For a more detailed look at June's climate, you can check Hammarby weather in June.

September weather tends to be cooler than July, with average temperatures ranging from a minimum of -1°C (31°F) to a maximum of 24°C (75°F), while July enjoys a warmer average of 6°C (43°F) to 32°C (90°F). Precipitation is slightly lower in September at 53 mm (2.1 in) over about 9 days compared to July's 70 mm (2.7 in) across 11 days, indicating that July is generally wetter. Additionally, September is more humid with an average humidity of 87%, whereas July has a lower humidity of 73%. For more specific details about July weather, you can refer to Hammarby weather in July.

In comparison to August, September experiences cooler temperatures, with minimums dipping to -1°C (31°F) compared to August's low of 3°C (38°F). The average temperature in September is 11°C (53°F), significantly lower than August’s average of 16°C (61°F). Maximum temperatures also fall, reaching up to 24°C (75°F) in September, whereas August sees highs of up to 30°C (85°F). Precipitation is present in both months, but September averages 53 mm (2.1 in) over 9 days, which is less than August's 90 mm (3.5 in) across 13 days, despite a higher humidity level in September at 87% compared to August's 78%. For a detailed look at August weather, visit Hammarby weather in August.

In September, the weather exhibits a pleasant range of temperatures, with a minimum of -1°C (31°F) and a maximum reaching 24°C (75°F), resulting in an average of 11°C (53°F). This month experiences 53 mm (2.1 in) of precipitation over 9 days and a relatively high humidity level of 87%. In contrast, October brings cooler temperatures, with minimums dropping to -5°C (23°F) and averages settling at 7°C (44°F). The maximum temperature in October is 20°C (68°F). Additionally, this month sees increased precipitation of 88 mm (3.5 in) over 13 days, alongside a higher humidity of 92%. For more detailed information, you can check Hammarby weather in October.

September experiences milder weather compared to November, with average temperatures ranging from a minimum of -1°C (31°F) to a maximum of 24°C (75°F). The month sees 53 mm (2.1 in) of precipitation over 9 days and maintains a humidity level of 87%. In contrast, November is considerably colder, featuring a minimum temperature of -12°C (11°F) and an average of only 2°C (36°F), while the maximum only reaches 14°C (58°F). Precipitation drops slightly to 49 mm (1.9 in) over the same 9 days, but humidity rises to 94%. This shift reflects the transition from early autumn warmth to the chill of late fall. You can explore more about the specific weather conditions in November at Hammarby weather in November.

In September, temperatures in Hammarby range from a chilly -1°C (31°F) at night to a pleasant 24°C (75°F) during the day, with an average of 11°C (53°F). The month sees around 53 mm (2.1 in) of precipitation across about 9 days, with humidity levels at 87%, creating a moderately comfortable atmosphere. In stark contrast, December brings a significant drop in temperatures, with lows plunging to -18°C (-1°F) and daytime highs reaching only up to 8°C (47°F), averaging -1°C (30°F). This winter month experiences slightly higher precipitation at 56 mm (2.2 in) over 13 days, but the humidity rises to a frosty 94%, making it feel much colder. For more details on December weather in Hammarby, check out Hammarby weather in December.

Compare Hammarby's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hammarby

As September unfolds in Hammarby, the weather showcases a unique transition from the warmth of summer to the crispness of autumn. Compared to the balmy days of summer, September sees a noticeable dip in temperature, with cooler average highs and lows, making it a month of cozy sweaters and brisk walks. The increased humidity adds a touch of dampness to the air, and with several days of precipitation, those iconic cloudy skies become more common. Overall, September serves as a gentle reminder of nature's shift, inviting both locals and visitors to appreciate the changing seasons. Discover more about what to expect throughout the year at Hammarby Climate.