September Weather in Stromness, United Kingdom

Last updated: March 17, 2025

In Stromness, United Kingdom, September showcases a temperate climate with an average temperature of 12°C (55°F), swinging from a maximum of 16°C (62°F) to a cooler minimum of 9°C (48°F). This month is characterized by significant precipitation, totaling 131 mm (5.2 in) spread over 19 days, contributing to a heightened humidity level of 88%. Visitors can expect a blend of crisp air and frequent rain, setting a tranquil atmosphere ideal for enjoying the scenic beauty of this coastal town.

September Temperature in Stromness

As September rolls into Stromness, temperatures begin to shift, offering a gentle transition from the warmth of summer to the crispness of autumn. The month showcases a mild climate with minimums around 9°C (48°F), averaging 12°C (55°F), and reaching maximums of 16°C (62°F). This pattern reflects a gradual cooling, yet the highs remain comparable to August, marking a balanced month that's neither too harsh nor too warm. The steady averages suggest comfortable days, making it an ideal time for exploring the scenic coastal landscapes or enjoying local culture before the chill of autumn sets in.

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

The chart illustrates September temperature patterns in Stromness, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec444343444751545554514845
Data source: Temperature data for Stromness 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 Stromness

September marks a notable shift in precipitation for Stromness, United Kingdom, with rainfall escalating to 131 mm (5.2 in) over the month. This represents a sharp increase compared to the drier summer months, where August recorded only 73 mm. In addition to heightened rainfall, the number of wet days rises to 19, indicating a more persistent pattern of wet weather as autumn approaches. This trend captures the transition from the relatively mild summer to the wet conditions typical of the fall, setting the stage for an even wetter October, which averages 168 mm. Overall, September serves as a reminder that the seasonal changes in Stromness can bring significant shifts in weather dynamics.

September Precipitation Trends in Stromness

The chart displays monthly precipitation patterns in Stromness, 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.
JanFebMarAprMayJunJulAugSepOctNovDec981051095361597373132168144117
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Stromness

As autumn approaches in Stromness, United Kingdom, September marks a noticeable peak in humidity, reaching 88%. This increase follows a summer trend where humidity levels were already elevated, with July and August at 87% and 86%, respectively. The transition from the warmer months to fall often brings a slight uptick in moisture, setting the stage for a cool yet damp ambiance. Notably, September's humidity is the highest of the year, which can make the air feel heavy, contrasting with the rest of the year where humidity hovers around the low to mid-80s. As the seasons shift, the lingering warmth of early autumn combined with the heightened humidity creates a unique atmospheric experience in Stromness.

September Average Humidity in Stromness

This chart illustrates the average monthly humidity levels in Stromness, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec82%81%81%81%83%84%87%86%88%87%87%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Stromness

As September rolls into Stromness, the UV Index settles at a moderate 4, indicating a shift from the high levels experienced during the summer months. With a burn time of 30 minutes, it's essential to stay sun-smart during outdoor activities. This transitional period showcases a gradual decrease in UV radiation; after reaching a peak of 7 in June and July, September marks a return to the more manageable levels akin to April and May. As autumn approaches, knowing how to protect your skin becomes increasingly important, especially with the lingering sunshine. For more details on daily UV exposure, check out the Stromness UV Index.

Maximum UV Index Levels in Stromness for September

The chart shows the monthly maximum UV Index (UVI) for Stromness 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.
JanFebMarAprMayJunJulAugSepOctNovDec113457754311
Data source: Stromness 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 Stromness

As September arrives in Stromness, the days are still graced with ample sunshine, boasting approximately 288 hours of daylight. This marks a significant decrease from the summer peak of 428 hours in June, yet it still offers a comforting warmth that lingers in the air. The gradual transition into autumn becomes apparent, as the sun's presence begins to dwindle, leading to shorter daylight hours that continue through October and into the winter months. The vibrant landscape, still brimming with life, showcases the beauty of the change as the community prepares for the cozy indoors. This interplay of light and shadow not only defines the rhythm of daily life but also emphasizes the charming resilience of Stromness as it welcomes the autumn season with open arms.

Monthly Sunshine Duration in Stromness: September Highlighted

The September sunshine duration represents the total number of hours Stromness 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.
JanFebMarAprMayJunJulAugSepOctNovDec55h141h204h337h406h428h413h384h288h209h94h74h
Data source: Stromness September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Stromness During September

In September, the likelihood of sunny weather in Stromness, United Kingdom hovers around 20%, reflecting a slight dip as summer transitions into autumn. This month typically experiences less sunshine compared to the bustling summer, with July and August recording their lowest probabilities at 15% and 14%, respectively. Interestingly, September’s forecast offers a modest improvement over the preceding months of June and July, where the chances of spotting sunshine falter. As autumn approaches, the days may grow shorter and cloudier, but the shifting seasons bring their own charm, transforming the landscape into a tapestry of rich fall colors.

Percentage of Sunny Days in September in Stromness

The chart illustrates the percentage of sunny days in Stromness 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 Stromness experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%35%19%35%27%26%15%14%20%20%20%23%
Data source: Stromness September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Stromness in September

As summer gives way to autumn, September in Stromness, United Kingdom, offers a gentle transition with 12 hours of daylight. This month marks a notable shift from the long, sun-filled days of June, where daylight peaked at 18 hours, to the shorter, cozier periods that characterize the fall. With daylight decreasing steadily from a summer high, September invites residents and visitors alike to embrace the lingering brightness while preparing for the earlier sunsets of October, which brings just 10 hours of daylight. The gradual drop reflects the rhythmic dance of the seasons, reminding us of nature's cycles and the approaching winter months.

Average Daylight Hours in Stromness for September

The chart illustrates the variation in daylight duration in Stromness throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 3m9h 16m11h 52m14h 31m16h 57m18h 20m17h 35m15h 20m12h 45m10h 8m7h 41m6h 18m
Data source: Stromness daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Stromness

As September unfolds in Stromness, the average wind speed settles at a refreshing 6.6 m/s (15 mph), marking a slight increase from the summer lull of July and August. This gentle breeze often signals the transition into the more robust autumn winds. Historically, as the year progresses, wind speeds in Stromness show a tendency to rise, peaking in November at 10.7 m/s (24 mph) before tapering off in the depths of winter. September, with its moderate winds, invites both locals and visitors to feel the invigorating change of season, where the air is charged with the promise of autumn’s return—crisp, lively, and full of character.

Average September Wind Speed in Stromness

The chart displays monthly wind speed patterns in Stromness, 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.
JanFebMarAprMayJunJulAugSepOctNovDec8.610.18.87.66.26.65.15.86.6 m/s9.010.78.8
Data source: Stromness September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Stromness Compares to Other Months

The weather in Stromness changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Stromness and find detailed weather information for every month.

In September, the weather is noticeably milder, with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F) and an average of 12°C (55°F). The month experiences a significant amount of rainfall, with 131 mm (5.2 in) falling over 19 days, contributing to a high humidity level of 88%. In contrast, January's weather is cooler, featuring a temperature range from 2°C (36°F) to a maximum of 12°C (53°F), with an average of 6°C (44°F). Although January has slightly less precipitation at 98 mm (3.9 in) over 16 days, the humidity drops to 82%. These differences highlight the transition from the relatively warm and wet conditions of September to the colder and drier climate of January. For a detailed look at January weather specifics, you can check Stromness weather in January.

In comparing the weather between September and February, September tends to be milder, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F), while February sees cooler conditions with temperatures ranging from 0°C (33°F) to 11°C (52°F). Precipitation levels are somewhat similar; September records about 131 mm (5.2 in) over 19 days, while February has slightly less at 105 mm (4.1 in), also spread across 19 days. Additionally, September experiences higher humidity at 88%, compared to 81% in February, making the latter month feel a bit drier. For more detailed insights, check out Stromness weather in February.

When comparing the weather in September and March, there are noticeable differences in temperature and precipitation. September typically enjoys a warmer climate, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F), while March sees much cooler conditions, with temperatures dipping to a minimum of -1°C (31°F) and only reaching a maximum of 10°C (50°F). Although both months experience considerable rainfall, September records slightly more precipitation at 131 mm (5.2 in) over 19 days compared to March's 109 mm (4.3 in) across 20 days. Additionally, September's humidity is higher at 88%, compared to March's 81%, highlighting that September is generally milder and more humid than March. For a detailed look at the weather conditions specifically in Stromness during March, you can visit Stromness weather in March.

When comparing the weather in September and April, notable differences emerge in both temperature and precipitation levels. September generally enjoys milder temperatures, with averages ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F), while April's temperatures are cooler, with a minimum of 0°C (32°F) and a maximum of just 12°C (53°F). Additionally, September experiences significantly higher precipitation, with 131 mm (5.2 in) over 19 days compared to April's 53 mm (2.1 in) across 12 days. The humidity levels also vary slightly, with September at 88% and April at 81%. For more specific details, you can check Stromness weather in April.

In September, the weather tends to be milder than in May, with average temperatures ranging from a low of 9°C (48°F) to a maximum of 16°C (62°F). The month also experiences higher precipitation levels, with 131 mm (5.2 in) over 19 days, resulting in a humidity level of 88%. In comparison, May sees cooler temperatures, with average lows of 3°C (37°F) and highs reaching only 14°C (57°F). Moisture levels are lower, with only 61 mm (2.4 in) of rain on 14 days, leading to a slightly drier atmosphere with 83% humidity. For more detailed insights on May weather, you can check Stromness weather in May.

When comparing the weather in September and June, September tends to be slightly warmer, with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F), compared to June's temperatures of 7°C (45°F) to 14°C (58°F). September also experiences significantly higher precipitation, measuring 131 mm (5.2 in) over 19 days, while June has only 59 mm (2.3 in) over 12 days. Additionally, the humidity is slightly higher in September at 88%, compared to June's 84%. For more specific details about June weather, you can explore Stromness weather in June.

In comparing the weather between September and July, both months exhibit similar minimum and average temperatures, with September showing slightly cooler conditions overall. September's maximum temperature reaches 16°C (62°F), just a degree lower than July's peak of 17°C (63°F). However, September is considerably wetter, with 131 mm (5.2 in) of precipitation occurring over 19 days, compared to July's 73 mm (2.9 in) over 15 days. Additionally, humidity levels remain relatively high in both months, at 88% for September and 87% for July. For more detailed insights, you can check Stromness weather in July.

In comparing the weather of September to August, September tends to be slightly cooler, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (62°F), while August sees slightly higher temperatures, with a minimum of 10°C (51°F) and a similar maximum of 16°C (61°F). Precipitation is notably higher in September, totaling 131 mm (5.2 in) over 19 days, compared to August's 73 mm (2.9 in) across 16 days. Humidity levels are also higher in September, at 88%, compared to August's 86%. For more detailed insights about August weather, you can visit Stromness weather in August.

In comparing the weather between September and October, we see a slight drop in temperatures as October features a minimum of 6°C (42°F) and a maximum of 15°C (59°F), compared to September's range of 9°C (48°F) to 16°C (62°F). Additionally, October tends to be wetter, with 168 mm (6.6 in) of precipitation occurring over 25 days, whereas September recorded 131 mm (5.2 in) across 19 days. Despite a minor decrease in humidity, which stands at 87% in October compared to 88% in September, the overall climate remains quite moist. For more details, you can check Stromness weather in October.

In comparing the weather between September and November, September typically enjoys milder temperatures, with a minimum of 9°C and a maximum of 16°C, while November cools down further to a minimum of 3°C and a maximum of 13°C. Precipitation also increases slightly in November, totaling 144 mm over 23 days compared to September's 131 mm over 19 days. Humidity levels remain quite similar, with September at 88% and November slightly lower at 87%. For more detailed information about November weather in Stromness, you can visit Stromness weather in November.

September typically experiences milder and warmer weather compared to December, with average temperatures ranging from a low of 9°C (48°F) to a high of 16°C (62°F). In contrast, December's temperatures are cooler, averaging between 3°C (37°F) and 12°C (53°F). While September sees slightly higher precipitation at 131 mm (5.2 in) over 19 days, December has a similar but slightly lower total of 117 mm (4.6 in) across 22 days, indicating a wetter month despite the overall cooler conditions. Additionally, humidity levels are higher in September at 88%, compared to December's 80%. For a closer look at the specifics of December weather, check out Stromness weather in December.

Compare Stromness's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Stromness

As September unfolds in Stromness, the weather begins to transition into the cooler embrace of autumn. With temperatures averaging a brisk 12°C (55°F), this month experiences a notable shift compared to the warmer summer months, inviting residents and visitors alike to don their light jackets. Rain is frequent, as indicated by 131 mm (5.2 in) of precipitation over 19 days, making it one of the wetter months of the year. The high humidity level of 88% adds to the chilly feeling, creating a distinct atmosphere that marks the departure from summer warmth. For those interested in a deeper look into the patterns of weather in this picturesque town, visit Stromness Climate.