September Weather in Kirkwall, United Kingdom

Last updated: March 17, 2025

In September, Kirkwall, United Kingdom experiences a cool maritime climate characterized by an average temperature of 12°C (54°F), with daily highs reaching a moderate 16°C (61°F) and lows dipping to 9°C (48°F). The month is notably wet, accumulating around 125 mm (4.9 in) of rainfall across 19 days, resulting in a humidity level of approximately 88%. This combination of mild temperatures and frequent precipitation creates a vibrant, lush landscape, making September an engaging time to experience the natural beauty of Kirkwall.

September Temperature in Kirkwall

As September rolls into Kirkwall, temperatures start to reflect the transition from summer's warmth towards autumn's chill. With a minimum temperature settling at 9°C (48°F) and an average of 12°C (54°F), it’s a time when the lingering summer feels gradually fade. The maximum temperature peaks at 16°C (61°F), similar to August, indicating that the month can still offer mild days perfect for exploring this charming town. However, as the month progresses, the steady decline from the highs of summer begins to set in, hinting at the changing seasons ahead. This blend of warmer early days followed by cooler nights underscores the gradual shift in the year as Kirkwall prepares for autumn.

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

The chart illustrates September temperature patterns in Kirkwall, 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 Kirkwall 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 Kirkwall

In September, Kirkwall experiences a notable increase in precipitation, with an average of 125 mm (4.9 in), making it one of the wettest months of the year. This month sees rain on approximately 19 days, contributing to a stark contrast from the relatively drier summer months of June, July, and August. The uptick in rainfall not only enhances the lush greenery that characterizes the Orkney Islands but also sets the stage for the wetter autumn ahead, as October typically follows suit with even higher precipitation levels. This trend signifies the transition from the mild summer climate to the more temperamental and rain-soaked conditions of autumn, reflecting Kirkwall's maritime climate dynamics.

September Precipitation Trends in Kirkwall

The chart displays monthly precipitation patterns in Kirkwall, 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.
JanFebMarAprMayJunJulAugSepOctNovDec91991045155557072125163136111
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Kirkwall

As the summer months fade away, September in Kirkwall, United Kingdom, ushers in a noticeable uptick in humidity, reaching a peak of 88%. This increase reflects the lingering warmth from August, which recorded 86% humidity, while also anticipating the more temperate conditions of autumn. The data reveals a clear trend: as the year progresses, humidity levels tend to rise, particularly from June onward, where values consistently hover in the mid-to-high 80s. Following September, October and November maintain this elevated humidity at 87%, creating a moist atmosphere that sets the stage for the upcoming winter months. Overall, September's humidity encapsulates the transitional essence of early autumn, offering a blend of warmth and moisture before the chill of winter establishes itself.

September Average Humidity in Kirkwall

This chart illustrates the average monthly humidity levels in Kirkwall, 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 Kirkwall

As September arrives in Kirkwall, United Kingdom, the UV Index reflects a shift towards milder sunlight, settling at a moderate level of 4. This indicates a burn time of about 30 minutes, encouraging residents and visitors to enjoy the outdoors while taking appropriate sun protection measures. Following the higher indices of summer, where values reached 7 in both June and July, September's UV Index begins to echo the more temperate conditions of early autumn. It's a time when the sun's rays are still strong enough to warrant attention, especially as the days gradually shorten. For more details on managing sun exposure throughout the year, explore the Kirkwall UV Index.

Maximum UV Index Levels in Kirkwall for September

The chart shows the monthly maximum UV Index (UVI) for Kirkwall 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: Kirkwall 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 Kirkwall

As September unfolds in Kirkwall, the lingering warmth of summer begins to fade, yet the month still boasts a commendable 288 hours of sunshine. This marks a notable drop from the vibrant glow of August's 384 hours, signaling the shift towards autumn's shorter days. However, when viewed in the context of the year, September shines brighter than the preceding months of October (209 hours) and November (94 hours), revealing an enduring edge of light before the winter gloom sets in. The trends show a gradual ascent in sunlight from the frigid depths of January up to June's peak at 428 hours, before it levels off in the late summer months. Thus, September serves as a perfect bridge, blending the aftermath of summer's brilliance with the onset of cooler, dimmer days ahead.

Monthly Sunshine Duration in Kirkwall: September Highlighted

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

Chance of Sun in Kirkwall During September

In September, Kirkwall experiences a modest 21% chance of sunny weather, slightly higher than the summer months of July and August, which both see a decrease in sunshine likelihood. This reflects a subtle shift as the region transitions from the warmer summer days to the cooler fall climate. Despite this uptick, the chances of basking in sunshine remain modest compared to the early spring and late autumn months, where sunshine probabilities generally hover around the 20% mark. As the days grow shorter, those hoping for bright sunny spells in September might find them elusive, yet there's still a glimmer of hope for some pleasant weather amid the changing seasons.

Percentage of Sunny Days in September in Kirkwall

The chart illustrates the percentage of sunny days in Kirkwall 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 Kirkwall experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec28%36%19%36%26%27%16%15%21%20%20%22%
Data source: Kirkwall September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Kirkwall in September

As September rolls into Kirkwall, the lingering warmth of late summer begins to fade, ushering in a noticeable shift in daylight. With around 12 hours of sunlight, the days are still fairly long compared to the winter months, yet they represent a clear decline from the sun-drenched 16 hours of May and the peak of 18 hours in June. This transition is a prelude to the shorter days ahead, as the sunlight dips to 10 hours in October and further dwindles to just 6 hours by December. The gradual decrease in daylight serves as a gentle reminder of the changing seasons, as Kirkwall prepares for the cozy embrace of autumn.

Average Daylight Hours in Kirkwall for September

The chart illustrates the variation in daylight duration in Kirkwall 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 17m
Data source: Kirkwall daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Kirkwall

As September arrives in Kirkwall, the wind begins to pick up slightly, averaging 6.7 m/s (15 mph), a modest increase from the summer's calmer breezes. This gentle gust is a prelude to the autumn months, which typically see stronger winds, peaking in November at 10.8 m/s (24 mph). Interestingly, the trend throughout the year reveals a gradual decline in wind speed from the blustery heights of mid-winter, averaging around 8.9 m/s (20 mph), down to the tranquil summer months. However, as the seasons shift, there's a notable resurgence in wind intensity, culminating in the dynamic transitions of autumn. September, with its mild winds, offers a perfect window to enjoy the crisp, refreshing air before the seasonal gales set in.

Average September Wind Speed in Kirkwall

The chart displays monthly wind speed patterns in Kirkwall, 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.
JanFebMarAprMayJunJulAugSepOctNovDec8.910.38.97.96.36.65.16.06.7 m/s9.210.88.9
Data source: Kirkwall September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Kirkwall Compares to Other Months

The weather in Kirkwall 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 Kirkwall and find detailed weather information for every month.

In September, the weather is generally milder, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (61°F), accompanied by significant rainfall of 125 mm (4.9 in) over 19 days and high humidity at 88%. In contrast, January temperatures drop further, with an average low of 2°C (36°F) and a high of only 12°C (53°F). Although January experiences less rainfall at 91 mm (3.6 in) over 16 days, the humidity remains relatively high at 82%. For more detailed insights, check out Kirkwall weather in January.

In comparing the weather of September and February, September generally offers milder temperatures with a minimum of 9°C (48°F) and a maximum of 16°C (61°F), compared to February's cooler range of 0°C (33°F) to 11°C (51°F). September also tends to be wetter, receiving 125 mm (4.9 in) of precipitation over 19 days, while February sees slightly less at 99 mm (3.9 in) over 18 days. Additionally, humidity levels are higher in September at 88%, compared to February's 81%. For more detailed information, you can check Kirkwall weather in February.

In comparing the weather between September and March, it’s clear that September tends to be milder with average temperatures ranging from 9°C (48°F) to 16°C (61°F), while March sees much colder conditions with temperatures from -1°C (31°F) to a maximum of 10°C (50°F). Additionally, September is significantly wetter, recording 125 mm (4.9 in) of precipitation over 19 days, compared to March's 104 mm (4.1 in) over 20 days. The humidity also remains higher in September at 88%, while March has a slightly lower humidity level of 81%. For a closer look at Kirkwall's weather in March, visit Kirkwall weather in March.

When comparing the weather in September and April, significant differences emerge in both temperature and precipitation. September tends to be milder, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (61°F), compared to April's chillier range of 0°C (32°F) to 11°C (53°F). Additionally, September experiences higher precipitation, totaling 125 mm (4.9 in) over 19 days, while April is considerably drier, with only 51 mm (2.0 in) falling across 12 days. Humidity is slightly higher in September at 88%, compared to 81% in April. This data highlights how early autumn in September is generally warmer and wetter than springtime in April. For more detailed information, you can check Kirkwall weather in April.

September tends to be milder than May, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (61°F). In contrast, May experiences cooler temperatures, with averages from a low of 3°C (37°F) to a high of 13°C (56°F). Additionally, September is notably wetter, receiving 125 mm (4.9 in) of precipitation over 19 days, compared to May's 55 mm (2.2 in) over just 13 days. Despite the increased rainfall in September, it maintains a slightly higher humidity level of 88%, while May has 83%. For more detailed weather insights, check Kirkwall weather in May.

In comparing the weather between September and June, September tends to be slightly warmer, with average temperatures ranging from 9°C (48°F) to a maximum of 16°C (61°F). In contrast, June generally sees temperatures between 7°C (45°F) and a maximum of 14°C (58°F), making June the cooler month of the two. Additionally, September experiences significantly more precipitation, with around 125 mm (4.9 in) falling over 19 days, compared to June's 55 mm (2.2 in) over just 11 days. Although both months have high humidity, September is slightly more humid at 88%, while June sits at 84%. For more detailed information, you can check out Kirkwall weather in June.

In comparing the weather between July and September, both months exhibit similar temperature ranges with minimums around 9°C and averages of 12°C. However, July tends to be slightly warmer, reaching an average maximum of 17°C compared to September’s maximum of 16°C. Precipitation levels are notably higher in September, with 125 mm over 19 days, in contrast to July's 70 mm over just 13 days, leading to a more humid atmosphere in September at 88%. For more detailed information about July weather, you can check this link: Kirkwall weather in July.

In comparing the weather between August and September, we can observe some notable differences. September tends to be slightly cooler, with a minimum temperature of 9°C (48°F) compared to August's minimum of 10°C (51°F). Both months share the same maximum temperature of 16°C (61°F), but September has a lower average temperature of 12°C (54°F), while August averages at 13°C (56°F). Additionally, September experiences significantly more precipitation, with 125 mm (4.9 in) over 19 days, in contrast to August's 72 mm (2.8 in) over 15 days. Humidity is also slightly higher in September at 88%, compared to 86% in August. For more detailed information about August weather in Kirkwall, you can visit Kirkwall weather in August.

In comparing the weather of September and October, we see a notable shift in both temperature and precipitation patterns. September tends to be slightly warmer, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (61°F), while October experiences cooler temperatures, with a minimum of 5°C (42°F) and a maximum of 15°C (59°F).

Precipitation also increases in October, reaching 163 mm (6.4 in) over 25 days, compared to September's 125 mm (4.9 in) across 19 days. Humidity remains relatively stable between the two months, with September at 88% and October at 87%. For more detailed insights, you can check Kirkwall weather in October.

September and November present distinct shifts in weather patterns. In September, temperatures range from a mild 9°C (48°F) to a comfortable high of 16°C (61°F), with an average of 12°C (54°F). The month sees considerable rainfall of 125 mm (4.9 in) over 19 days, coupled with high humidity levels at 88%. In contrast, November experiences cooler conditions with minimum temperatures dropping to 3°C (38°F) and a maximum of 13°C (56°F), averaging at 9°C (48°F). Precipitation increases slightly to 136 mm (5.4 in) across 23 days, with humidity remaining relatively constant at 87%. To learn more about weather specifics in November, check out Kirkwall weather in November.

In September, weather conditions are generally milder with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 16°C (61°F), accompanied by significant rainfall of 125 mm (4.9 in) over 19 days and high humidity levels at 88%. In contrast, December sees cooler temperatures, with an average range from 3°C (37°F) to 11°C (52°F), slightly less precipitation at 111 mm (4.4 in) over a similar number of rainy days (21), and lower humidity at 80%. This shift reflects the transition from early autumn to the depths of winter, with September generally offering a more temperate climate than December. For more details, check out Kirkwall weather in December.

Compare Kirkwall's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Kirkwall

As summer transitions to autumn, September in Kirkwall showcases a notable shift in weather patterns compared to the warmer months. With cooler average temperatures around 12°C, the crisp air invites a change in attire, while increased precipitation—spanning nearly two-thirds of the month—brings refreshing rains that nurture the landscape. The high humidity of 88% adds to the chill, making it feel cooler than it actually is. In contrast to the milder summers, September demands a cosier wardrobe and a readiness for wetter days. For a deeper look into Kirkwall's weather trends throughout the year, explore Kirkwall Climate.