September Weather in Clapham, United Kingdom

Last updated: March 17, 2025

In Clapham, United Kingdom, September weather offers a unique blend of warmth and moisture. With maximum temperatures reaching 29°C (85°F), the month can feel quite balmy, although the average settles around a comfortable 15°C (59°F). Temperatures can dip as low as 3°C (37°F), reminding residents of the approaching autumn. Rainfall is not uncommon, with 52 mm (2.0 inches) of precipitation spread over 9 days, contributing to a humidity level of 85% that keeps the air fresh yet slightly damp. This dynamic climate makes September an interesting time to experience the beauty of Clapham.

September Temperature in Clapham

In September, Clapham experiences a delightful transition from the summer heat to the cooler embrace of autumn. With minimum temperatures around 3°C (37°F) and a comfortable average of 15°C (59°F), it offers a refreshing reprieve from the highs of summer. The maximum temperature can soar up to 29°C (85°F), hinting at lingering warmth before the chill sets in. This month beautifully encapsulates the shift in seasons, with the air becoming crisp and inviting, making it a perfect time for outdoor activities and enjoying the vibrant colors of early fall. As September unfolds, Clapham residents relish the extended daylight while savoring the gradual cooling that hints at the cozy months ahead.

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

The chart illustrates September temperature patterns in Clapham, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec404345485461656459534643
Data source: Temperature data for Clapham 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 Clapham

In September, Clapham experiences a moderating shift in precipitation patterns, with 52 mm (2.0 in) of rain spread over 9 days. This marks a slight decrease in both total rainfall and rainy days compared to the preceding summer months of August, which saw 70 mm over 12 days. As autumn approaches, the weather tends to become more variable, but September maintains a comfortable balance, reminiscent of the earlier summer months while hinting at the wetter conditions to come in October, where precipitation spikes to 84 mm (3.3 in). This transition not only reflects the deepening of the seasonal change but also emphasizes the region's typical trend of increasing rainfall as the year progresses.

September Precipitation Trends in Clapham

The chart displays monthly precipitation patterns in Clapham, 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.
JanFebMarAprMayJunJulAugSepOctNovDec504757386473687052845378
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Clapham

As September arrives in Clapham, the air takes on a slightly more humid character, with humidity levels rising to 85%. This increase follows the summer months, where humidity dipped to its lowest at 76% in July, creating a refreshing contrast. While the late summer air retains some warmth, the gradual climb in humidity from 77% in August signals the approaching autumn, reminiscent of the earlier months in the year. Interestingly, as the season transitions, Clapham's humidity is poised to rise again, aligning closely with the significantly higher levels of 90% observed in both October and December. Each month tells a story, revealing the ebb and flow of moisture in the air, with September acting as a bridge between declining summer warmth and the cooler, wetter weeks ahead.

September Average Humidity in Clapham

This chart illustrates the average monthly humidity levels in Clapham, 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%84%80%81%76%77%85%90%92%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Clapham

As September rolls in, Clapham experiences a moderate UV Index of 5, signaling a shift from the peak summer levels. This gradual decline, yet still prominent presence of UV rays, suggests that while the days are starting to cool, sun protection remains essential. With a burn time of 30 minutes, residents and visitors alike are reminded to enjoy the outdoor scenery while taking precautions against sun exposure. This trend of decreasing UV levels will continue into October, showcasing the transitional nature of the seasons. For more detailed insights and updates, check Clapham UV Index.

Maximum UV Index Levels in Clapham for September

The chart shows the monthly maximum UV Index (UVI) for Clapham 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Clapham 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 Clapham

As summer gently fades, September in Clapham still welcomes a generous 286 hours of sunshine, providing a warm embrace before the cooler months arrive. This month reflects a transition, showcasing a noticeable drop from the sun-drenched days of July and August, but still significantly better than the grey days of winter ahead. With its sunny hours peaking in May and July, Clapham experiences a gradual decline into autumn, yet September serves as a vibrant bridge, allowing residents to savor the lingering warmth. As the days shorten and the crispness of October approaches, this month's sunshine invites leisurely strolls in the parks and outdoor gatherings, reminding us of summer's lasting charm.

Monthly Sunshine Duration in Clapham: September Highlighted

The September sunshine duration represents the total number of hours Clapham 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.
JanFebMarAprMayJunJulAugSepOctNovDec90h147h204h307h378h361h382h352h286h229h138h103h
Data source: Clapham September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Clapham During September

In Clapham, United Kingdom, the likelihood of sunny weather in September stands at a moderate 29%, reflecting a transitional period as summer wanes. This percentage marks an increase from the sunniest months of April and July, but remains somewhat subdued compared to the preceding summer months, where June and August hover around the 25% and 24% chances of sunshine, respectively. As the year progresses toward autumn, the prospect of sunshine tends to dip, with September offering a mix of lingering summer warmth and the encroaching chill of fall. Thus, while it’s a decent opportunity for sunny days, it also signals the need to keep an umbrella close at hand as the weather begins to shift.

Percentage of Sunny Days in September in Clapham

The chart illustrates the percentage of sunny days in Clapham 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 Clapham experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec23%25%26%48%30%25%38%24%30%22%31%16%
Data source: Clapham September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Clapham in September

As September unfolds in Clapham, UK, the days begin to shorten, offering approximately 12 hours of daylight. This marks a gentle transition from the vibrant summer months, which reached their peak with 16 hours of radiant light in June and July, gradually tapering off through August's 14 hours. The trend continues into the autumn, where daylight decreases to 10 hours by October, hinting at the longer, cozier nights ahead. While the days are still pleasantly illuminated, the changing light serves as a reminder of the seasonal shift, enriching the experience of early autumn strolls as the landscape transforms.

Average Daylight Hours in Clapham for September

The chart illustrates the variation in daylight duration in Clapham throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 18m9h 55m11h 54m13h 56m15h 43m16h 39m16h 9m14h 33m12h 35m10h 34m8h 45m7h 47m
Data source: Clapham daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Clapham

As September arrives in Clapham, the breeze begins to cool, with an average wind speed of 3.6 m/s (8 mph) marking a gentle transition into autumn. Following a slightly warmer summer, where August recorded a wind speed of 4.1 m/s, September’s winds are notably calmer, reminiscent of the more tranquil conditions from earlier in the season, such as those seen in June and July. This month’s winds are relatively moderate compared to the gusty start of the year, suggesting a gradual shift towards the more vibrant and changeable weather of autumn. As we move into October, a return to higher gusts at 5.0 m/s (11 mph) is expected, reinforcing nature’s rhythm as the seasons shift, emphasizing the dynamic and ever-changing character of Clapham's weather patterns.

Average September Wind Speed in Clapham

The chart displays monthly wind speed patterns in Clapham, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.55.04.73.54.33.43.24.13.6 m/s5.04.44.8
Data source: Clapham September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Clapham Compares to Other Months

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

In comparing the weather in September and January, we see significant differences in temperature and conditions. September enjoys a milder climate, with average temperatures ranging from a minimum of 3°C (37°F) to a pleasant maximum of 29°C (85°F), accompanied by relatively low precipitation of 52 mm (2.0 in) over 9 days and a humidity level of 85%. In contrast, January is much colder, with temperatures dipping to a minimum of -4°C (25°F) and only reaching an average high of 14°C (58°F). Despite a similar level of precipitation at 50 mm (2.0 in) over the same number of days, January's humidity rises slightly to 90%, making the air feel even chillier. For more detailed insights into January weather, check out Clapham weather in January.

September and February showcase significantly different weather patterns. In September, temperatures range from a mild 3°C (37°F) at night to a maximum of 29°C (85°F) during the day, with an average temperature of 15°C (59°F). This month sees about 52 mm (2.0 in) of precipitation over approximately 9 days and a humidity level of 85%. In contrast, February experiences cooler temperatures, dipping as low as -6°C (22°F) at night and peaking at 18°C (65°F) during the day, with an average of 6°C (43°F). Precipitation in February is slightly lower at 47 mm (1.9 in) over about 11 days, accompanied by a humidity level of 88%. For more details, you can check Clapham weather in February.

In comparing the weather in September and March, September generally offers milder temperatures, with averages around 15°C (59°F) and maximums reaching up to 29°C (85°F), in stark contrast to March's cooler averages of 7°C (45°F) and maximums of 22°C (71°F). However, March experiences more chilly nights, with minimum temperatures dropping as low as -7°C (20°F). Both months see a fair amount of precipitation, with September receiving around 52 mm (2.0 in) over 9 days, while March records slightly more at 57 mm (2.2 in) across 13 days. Humidity remains high in both months, with September at 85% and March at 86%, adding a distinct feel to the air. For a closer look at conditions during March, you can explore Clapham weather in March.

When comparing September and April weather, September tends to be warmer, with average temperatures reaching 15°C (59°F) and maximums of 29°C (85°F), while April has a cooler average of 9°C (49°F). Although both months experience similar humidity levels, September is slightly more humid at 85%, compared to April's 84%. Precipitation is relatively close, with September receiving 52 mm (2.0 in) over 9 days, while April has 38 mm (1.5 in) across 8 days. For a detailed look at April's weather, you can visit Clapham weather in April.

When comparing the weather in September and May, a few key differences emerge. September tends to feature a wider temperature range, with minimums around 3°C (37°F) and maximums peaking at 29°C (85°F), leading to an average of 15°C (59°F). In contrast, May generally sees cooler temperatures, with average lows of 1°C (34°F) and highs reaching 27°C (80°F), resulting in an average of 12°C (55°F). Additionally, September experiences slightly less precipitation at 52 mm (2.0 in) over 9 days, compared to May's 64 mm (2.5 in) over 11 days. While humidity levels are relatively high in both months—85% in September and 80% in May—these figures indicate that both times of year can feel quite damp. For those interested in more detailed weather patterns, check out Clapham weather in May.

In comparing the weather between September and June, we see notable differences in temperature and precipitation patterns. September typically experiences a minimum temperature of 3°C (37°F), with an average of 15°C (59°F) and a maximum reaching 29°C (85°F), making for warm daytime conditions, but cooler nights. In contrast, June has slightly milder temperatures, with a minimum of 6°C (44°F), an average of 16°C (61°F), and a maximum of 31°C (88°F), resulting in generally warmer days. Regarding precipitation, June averages higher rainfall at 73 mm (2.9 in) across 10 days compared to September's 52 mm (2.0 in) over 9 days. Humidity levels are also high, with September at 85% and June slightly lower at 81%. For more detailed information on the weather in June, you can check Clapham weather in June.

September offers a more varied temperature range compared to July, with minimums dipping to 3°C (37°F) while still reaching a pleasant average of 15°C (59°F) and maximums peaking at 29°C (85°F). In contrast, July boasts higher minimum temperatures starting at 7°C (45°F) and an average of 18°C (65°F), with maximums soaring up to 37°C (98°F). While both months experience rainfall, September has 52 mm (2.0 in) over 9 days, making it slightly drier than July, which sees 68 mm (2.7 in) across 14 days. Furthermore, September's humidity level is higher at 85%, compared to July’s 76%. For a more detailed look at July weather, you can check Clapham weather in July.

In comparing the weather of September to that of August, September showcases a significant drop in temperatures, with a minimum of 3°C compared to August's 8°C, and a cooler average of 15°C against August's 18°C. The maximum temperature in September reaches 29°C, which is notably lower than August's peak of 35°C. Additionally, September experiences slightly less precipitation at 52 mm over 9 days, compared to August's 70 mm over 12 days. However, the humidity rises to 85% in September, higher than August's 77%. For more details on August's climate, you can visit Clapham weather in August.

September and October weather presents a noticeable transition as autumn sets in. In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 29°C (85°F), with an average of 15°C (59°F). The month typically sees 52 mm (2.0 in) of precipitation over 9 days, coupled with a relatively high humidity of 85%. In contrast, October brings cooler conditions, with temperatures dipping to a minimum of 0°C (33°F) and a maximum of 23°C (74°F), averaging at 11°C (53°F). Additionally, October experiences increased precipitation at 84 mm (3.3 in) over 12 days, and even higher humidity at 90%. For more detailed insights, visit Clapham weather in October.

In September, temperatures range from a mild minimum of 3°C (37°F) to a warm maximum of 29°C (85°F), with an average of 15°C (59°F). The month sees moderate rainfall of 52 mm (2.0 in) over about 9 days and maintains a high humidity level of 85%. In contrast, November brings cooler temperatures, starting with a minimum of -3°C (28°F) and a maximum of 17°C (63°F), yielding an average of 8°C (46°F). Precipitation slightly increases to 53 mm (2.1 in) across 10 days, while humidity rises to 92%. For more detailed information, check out Clapham weather in November.

September generally offers milder temperatures, with averages around 15°C (59°F), allowing for more pleasant outdoor activities. The month experiences a wider range of temperatures, from a minimum of 3°C (37°F) to a maximum of 29°C (85°F), along with about 52 mm (2.0 in) of precipitation over approximately 9 days. In contrast, December sees much colder weather, with average temperatures dropping to 6°C (43°F) and a minimum of -4°C (25°F), making outdoor conditions less inviting. Additionally, December tends to have higher precipitation levels, at 78 mm (3.1 in) over about 15 days, coupled with increased humidity at 90%. For more details on December weather specifics, visit Clapham weather in December.

Compare Clapham's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Clapham

As summer transitions to autumn, September in Clapham showcases a delightful mix of warmth and refreshing conditions. While the month can still experience pleasantly warm days, peaking at 29°C, the overall feel shifts significantly with cooler nights and an average temperature that dips towards 15°C. With humidity levels climbing to 85% and rain gracing about nine days, this month introduces a hint of unpredictability, contrasting sharply with the drier summer months. As you prepare for the change in weather, explore more about what to expect this season at Clapham Climate.