September Weather in Keswick, United Kingdom

Last updated: March 17, 2025

In September, Keswick, United Kingdom, experiences a varied climate that captivates both locals and visitors alike. With a maximum temperature reaching 26°C (79°F), the month can surprise with its warmth, while the average temperature settles at a cooler 13°C (55°F). Frequent rain showers are common, with 140 mm (5.5 in) of precipitation falling over 17 days, fostering a lush and vibrant landscape. The humidity, often hovering at 88%, adds a refreshing touch to the crisp autumn air. Whether you're exploring the scenic trails or relaxing by a cozy fire, September in Keswick offers a unique blend of mild temperatures and frequent rainfall that perfectly encapsulates the beauty of the Lake District.

September Temperature in Keswick

In September, Keswick, United Kingdom experiences a notable transition towards autumn, with temperatures that gently taper off from the warm summer months. The minimum temperature settles at a crisp 2°C (36°F), while the average climbs to a pleasant 13°C (55°F), offering a sense of mildness before the chill of fall sets in. Interestingly, the maximum temperature maintains a comfortable 26°C (79°F), reflecting a lingering warmth reminiscent of late summer. This month serves as a bridge, where the vibrant colors of early autumn begin to emerge against a backdrop of typically stable weather, making it an inviting time for exploration and enjoyment of the stunning Lake District scenery.

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

The chart illustrates September temperature patterns in Keswick, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec404142465157595955504541
Data source: Temperature data for Keswick 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 Keswick

September in Keswick often marks a continuation of the late summer rains, with precipitation averaging 140 mm (5.5 in) over 17 days. This level of rainfall maintains a consistent pattern established in the preceding months, particularly with August’s significant 167 mm (6.6 in). As autumn approaches, the prevalence of rain begins to intensify, setting the stage for October, which typically sees even higher totals. The transition from summer to autumn is clearly reflected in the increasing number of precipitation days, hinting at the region's shift towards the wetter months ahead.

September Precipitation Trends in Keswick

The chart displays monthly precipitation patterns in Keswick, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1041631385673115110167140193138158
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Keswick

In September, Keswick's humidity experiences a noticeable uptick to 88%, echoing the wetter months that lie ahead. This slight increase comes after a summer of relatively stable humidity levels, lingering around 82% in both July and August. As the year progresses from the drier spring months, where humidity dipped to 80% in May and maintained a gradual decline, September hints at the onset of autumn's chill, reminiscent of January's humid peak at 90%. The trend reveals a cyclical pattern where humidity levels rise significantly as the year transitions from summer to the wetter autumn months, suggesting that residents should prepare for the brisk and moisture-laden air of October and November.

September Average Humidity in Keswick

This chart illustrates the average monthly humidity levels in Keswick, 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.
JanFebMarAprMayJunJulAugSepOctNovDec90%88%86%85%81%83%82%82%88%90%92%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Keswick

As September rolls into Keswick, the UV Index takes a moderate dip to 5, offering a more manageable sun exposure as the summer warmth begins to wane. With a burn time of approximately 30 minutes, it emphasizes the need for mindful sun protection, particularly during peak hours. This trend follows a summer season characterized by very high UV levels, peaking at 8 in the previous months. Interestingly, September's UV Index mirrors that of April, showcasing a gradual return to milder conditions while still reminding us to remain vigilant outdoors. To see how the UV Index changes throughout the year, visit Keswick UV Index.

Maximum UV Index Levels in Keswick for September

The chart shows the monthly maximum UV Index (UVI) for Keswick 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Keswick 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 Keswick

As the summer fades, September in Keswick unveils a gentle embrace of sunshine, offering a delightful 296 hours of bright days. This month marks a transition, with daylight hours still ample but gradually succumbing to autumn's approach. Following the sun-drenched peak of July, which boasts an impressive 406 hours, September’s light provides a soothing, golden glow that invites locals and visitors alike to enjoy the lingering warmth of the season. This steady decline from summer’s zenith reflects a broader trend: after the flowers bloom in springtime and bask in the early summer sun, the hours of sunshine gradually diminish toward the chilly embrace of winter, reaching a mere 91 hours in December. Yet, September stands as a testament to autumn's charm, capturing the essence of nature’s vibrant cycle.

Monthly Sunshine Duration in Keswick: September Highlighted

The September sunshine duration represents the total number of hours Keswick 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.
JanFebMarAprMayJunJulAugSepOctNovDec80h145h210h340h405h386h406h358h296h228h114h91h
Data source: Keswick September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Keswick During September

September in Keswick, United Kingdom, brings a modest likelihood of sunshine, with only a 19% chance of sunny days. This marks a decline from the more promising 53% in April and a notable dip compared to late summer months, where opportunities for sunshine hover around 24% in August and 38% in July. As the seasons shift toward autumn, the weather becomes less predictable, hinting at a transition of warm, sunny days to cooler, cloudier ones. Thus, while September may not offer an abundance of sunshine, it still stands as a month of striking beauty, where the changing leaves complement the occasional bright sky.

Percentage of Sunny Days in September in Keswick

The chart illustrates the percentage of sunny days in Keswick 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 Keswick experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec21%26%23%53%31%21%38%25%19%16%27%14%
Data source: Keswick September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Keswick in September

As summer transitions into autumn, September in Keswick, United Kingdom, offers a delightful balance of daylight, averaging around 12 hours. The month marks a noticeable decline from the sun-soaked days of August, which boasted 14 hours, hinting at the impending shorter days of fall. This gentle reduction in daylight signals the gradual shift in seasons, as longer evenings begin to embrace the picturesque landscapes of the Lake District. Following this trend, October will further shorten the days to 10 hours, reinforcing the rhythm of nature’s cycle. As daylight wanes, September provides a beautiful opportunity to savor those lingering sunny moments before the crispness of autumn sets in.

Average Daylight Hours in Keswick for September

The chart illustrates the variation in daylight duration in Keswick throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 55m9h 43m11h 54m14h 7m16h 6m17h 9m16h 35m14h 48m12h 38m10h 26m8h 25m7h 20m
Data source: Keswick daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Keswick

As September rolls into Keswick, the winds greet the changing season with a gentle touch, averaging 3.2 m/s (7 mph). This consistent breeze mirrors late summer's softer gales, maintaining a steady rhythm from August. After a calm July with its lowest wind speeds of 2.4 m/s (5 mph), the air begins to stir a bit more, hinting at the upcoming autumn transition. Looking ahead, the winds are set to pick up in October with an average of 5.0 m/s (11 mph), suggesting a shift towards more vigorous weather patterns, while the overall trend reveals that autumn is on the horizon, promising a dynamic interplay of scenery and elements in the beautiful Lake District.

Average September Wind Speed in Keswick

The chart displays monthly wind speed patterns in Keswick, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.65.24.52.93.43.22.43.23.2 m/s5.04.54.1
Data source: Keswick September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Keswick Compares to Other Months

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

In September, temperatures in Keswick range from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), with an average of 13°C (55°F). This month also sees significant rainfall, with 140 mm (5.5 in) spread over 17 days and humidity levels around 88%. In contrast, January presents a much colder climate, with temperatures dropping to a minimum of -6°C (22°F) and only reaching a maximum of 12°C (55°F), averaging at 4°C (40°F). January experiences less precipitation at 104 mm (4.1 in) over 14 days, but slightly higher humidity at 90%. For more details on the winter conditions, see Keswick weather in January.

Comparing September and February weather reveals distinct seasonal differences. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), with an average of 13°C (55°F). The month features 140 mm (5.5 in) of precipitation spread across 17 days and maintains high humidity at 88%. In contrast, February experiences colder temperatures, ranging from a low of -7°C (20°F) to a maximum of 16°C (61°F), with an average of 5°C (41°F). It sees slightly more precipitation at 163 mm (6.4 in) over the same number of days and also has a humidity level of 88%. For a more detailed understanding of February weather, you can visit Keswick weather in February.

September generally offers milder temperatures compared to March, with average highs reaching up to 26°C (79°F) and lows rarely dropping below 2°C (36°F). In contrast, March can be quite chilly, featuring average lows around -5°C (23°F) and highs of only 17°C (62°F). Both months experience similar precipitation levels, with September receiving 140 mm (5.5 in) and March slightly less at 138 mm (5.4 in), and both see rain on about 17 days. Humidity levels are also comparable, with September at 88% and March at 86%. For more detailed insights about the weather in March, you can check Keswick weather in March.

The weather in September is generally milder than in April, with average temperatures ranging from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), compared to April's range of -3°C (27°F) to 20°C (69°F). Additionally, September experiences significantly more precipitation, averaging 140 mm (5.5 in) over 17 days, while April sees only 56 mm (2.2 in) across 10 days. Humidity levels are relatively similar in both months, with September slightly higher at 88% and April at 85%. For a more detailed view of April conditions, you can check out Keswick weather in April.

When comparing the weather in September and May, we see notable differences in temperature and precipitation levels. September tends to be warmer overall, with average temperatures reaching 13°C (55°F) and maximums climbing to 26°C (79°F), while May has a slightly cooler average of 11°C (51°F) and a maximum of 25°C (77°F). Additionally, September experiences significantly more rainfall, with 140 mm (5.5 in) over 17 days compared to May's 73 mm (2.9 in) across 13 days. Humidity is relatively high in both months, but September holds a slight edge at 88% compared to May's 80%. For a detailed look at the conditions you can expect, check out Keswick weather in May.

When comparing the weather in September and June, we see that September tends to be slightly cooler on average, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), while June has a range of 5°C (41°F) to 27°C (81°F). Precipitation is a bit higher in September, with 140 mm (5.5 in) spread across 17 days compared to June's 115 mm (4.5 in) over 15 days. Additionally, September is marked by higher humidity levels at 88% compared to June's 83%. For a more detailed look at the June weather, check out Keswick weather in June.

In comparing the weather of September and July, September presents cooler temperatures, with minimums dipping to 2°C (36°F) compared to July’s minimum of 7°C (44°F). The average temperature in September is 13°C (55°F), slightly lower than July's 15°C (60°F), and while July boasts a higher maximum temperature of 29°C (84°F), September reaches a pleasant high of 26°C (79°F). Precipitation levels are notably higher in September, with 140 mm (5.5 in) occurring over 17 days, compared to July’s 110 mm (4.3 in) over 16 days. Additionally, September's humidity is slightly elevated at 88%, while July's humidity sits at 82%. For more detailed information about July's weather, you can check the link: Keswick weather in July.

In comparing the weather between September and August, we see some notable differences. September's temperatures range from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), with an average of 13°C (55°F), showing a slight drop in overall warmth compared to August, which has a minimum of 6°C (43°F) and an average of 15°C (59°F). Both months have the same maximum temperature of 26°C (79°F), but September experiences more rainfall with 140 mm (5.5 in) over 17 days compared to August's 167 mm (6.6 in) over 20 days. Additionally, September is slightly more humid, with humidity levels at 88% compared to August's 82%. For more detailed information on August weather, you can visit Keswick weather in August.

September and October bring notable changes in weather patterns. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 26°C (79°F), with an average of 13°C (55°F). The month experiences about 140 mm (5.5 in) of precipitation over 17 days and maintains a high humidity level of 88%. In contrast, October sees a drop in temperatures, with a minimum of -3°C (27°F) and a maximum of 20°C (69°F), averaging around 10°C (50°F). Precipitation increases to 193 mm (7.6 in) across 21 days, with humidity slightly rising to 90%. For a more detailed look at October weather, visit Keswick weather in October.

September and November present contrasting weather patterns as summer transitions to winter. In September, temperatures range from a mild 2°C (36°F) at night to a pleasant maximum of 26°C (79°F) during the day, with an average of 13°C (55°F). The month sees an overall higher humidity of 88% and experiences about 140 mm (5.5 in) of precipitation over 17 days. In contrast, November showcases a cooler climate, with temperatures dipping down to a minimum of -4°C (26°F) and an average of 7°C (45°F), peaking at only 13°C (56°F). This month has a similar precipitation level of 138 mm (5.4 in) but over 18 days, paired with an increased humidity of 92%. For more detailed insights into the specifics of November weather, you can visit Keswick weather in November.

September and December present distinctly different weather patterns. In September, temperatures range from a mild 2°C (36°F) at night to a pleasant 26°C (79°F) during the day, with an average of 13°C (55°F). The month sees considerable rainfall, totaling 140 mm (5.5 in) over 17 days, with humidity levels at a high 88%. In contrast, December offers colder conditions, with minimum temperatures dropping to -6°C (21°F) and a maximum of 12°C (53°F), averaging around 5°C (42°F). Rainfall increases slightly to 158 mm (6.2 in) over 19 days, and humidity remains consistently high at 89%. For more detailed insights on December weather, visit Keswick weather in December.

Compare Keswick's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Keswick

As September unfolds in Keswick, the transition from summer to autumn becomes evident, bringing with it a unique blend of weather characteristics. Temperatures begin to cool, with a noticeable drop from the summer highs, while the persistent humidity of 88% often makes the air feel heavier. Rain is more frequent this month, with precipitation spread over nearly half the month, which contributes to the lush greenery that characterizes this picturesque region. Compared to other months, September ushers in a more dynamic climate, making it an intriguing time to experience Keswick’s scenic beauty. For a more detailed view of the local climate patterns, be sure to check out Keswick Climate.