September Weather in Hounslow, United Kingdom

Last updated: March 17, 2025

In September, Hounslow, United Kingdom, experiences a dynamic climate characterized by a maximum temperature reaching 28°C (83°F), suggesting warm and sunny days, balanced by an average of 15°C (59°F). While the weather can still feel mild, cooler nights bring temperatures down to a refreshing minimum of 4°C (39°F). This month also sees precipitation amounting to 45 mm (1.8 in) spread over 10 days, resulting in an humidity level of 82% that can add a touch of dampness to the air. Overall, September in Hounslow offers a blend of warmth and moisture, perfect for enjoying the early days of autumn.

September Temperature in Hounslow

As September rolls in, Hounslow experiences a delightful transition into early autumn. With minimum temperatures averaging around 4°C (39°F) and highs peaking at a pleasant 28°C (83°F), the month offers a comfortable backdrop for outdoor exploration. This balance of warmth and crispness is reflected in the average temperature of 15°C (59°F), making it an ideal time for leisurely strolls in the park or enjoying local festivals. Compared to the sweltering peak summer months, September provides a refreshing respite, with a slight coolness that hints at the impending change of seasons, ensuring that both residents and visitors can relish the rich tapestry of early autumn in this vibrant part of the United Kingdom.

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

The chart illustrates September temperature patterns in Hounslow, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec414345495562656459534643
Data source: Temperature data for Hounslow 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 Hounslow

In September, Hounslow experiences a moderate precipitation level, with 45 mm (1.8 in) of rain falling over approximately 10 days. This marks a slight decrease compared to the wetter months of June and August, which saw rainfall of 77 mm (3.0 in) and 70 mm (2.7 in), respectively. As summer gives way to autumn, the transition is reflected in the rainfall patterns, where September often serves as a bridge that hints at the wetter conditions to come in October, which typically averages 84 mm (3.3 in). Overall, while September offers a respite from the heaviest rains of summer, it still maintains a consistent rhythm of periodic showers, fostering the lush greenery for which the region is known.

September Precipitation Trends in Hounslow

The chart displays monthly precipitation patterns in Hounslow, 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.
JanFebMarAprMayJunJulAugSepOctNovDec545354336277647045845284
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hounslow

As summer transitions to autumn in Hounslow, September brings an average humidity of 82%, a noticeable rise from the drier months of July and August. This uptick signals the shift in season, where the air grows heavier with moisture, setting the stage for the wetter months ahead. Throughout the year, Hounslow experiences a gradual increase in humidity from the chilly depths of winter, peaking in the last few months of the year, where figures climb to an impressive 92% by November and December. The humidity levels in September, while still comfortable compared to the depths of winter, serve as a gentle reminder that autumn is on the horizon, inviting a fresh crispness to the air.

September Average Humidity in Hounslow

This chart illustrates the average monthly humidity levels in Hounslow, 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.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%86%85%79%81%71%76%82%91%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hounslow

In September, Hounslow experiences a UV Index of 6, categorized as high, which calls for an awareness of sun exposure. As the summer warmth begins to wane, the UV levels drop slightly from August's peak of 7, yet they remain significant enough to warrant caution. With a burn time of just 25 minutes, it’s essential for residents and visitors to take protective measures when outdoors. This trend reflects a gentle transition from the intense summer sun towards the milder months, highlighting the importance of adapting skincare routines with the changing seasons. For more detailed information on UV levels throughout the year, visit Hounslow UV Index.

Maximum UV Index Levels in Hounslow for September

The chart shows the monthly maximum UV Index (UVI) for Hounslow 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578876421
Data source: Hounslow 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 Hounslow

As September arrives in Hounslow, the lingering warmth of summer is evident, with the month basking in 300 hours of sunshine. This marks a slight dip from the sun-soaked heights of July and August, which boasted over 400 hours each, yet September still benefits from the remnants of summer's glow. Following a steady rise through the spring months, where sunlight gracefully blossomed from 210 hours in March to 398 hours in May, September continues to showcase a significant amount of daylight. As we transition into autumn, the decrease parallels the upcoming months, notably October's drop to 241 hours. This trend hints at shorter days ahead, but until then, September in Hounslow invites residents and visitors alike to relish in the golden sunshine before the frosty touch of winter sets in.

Monthly Sunshine Duration in Hounslow: September Highlighted

The September sunshine duration represents the total number of hours Hounslow 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.
JanFebMarAprMayJunJulAugSepOctNovDec98h148h210h319h398h389h404h368h300h241h144h109h
Data source: Hounslow September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hounslow During September

In Hounslow, September emerges as a transition month in the quest for sunny weather, with a 29% chance of sun. This is fairly consistent with previous months, such as March and August, which also hover around the same likelihood of sunshine. Notably, the sunny prospects begin to decline from the vibrant warmth of late spring and early summer, where April peaks at 49% before settling into the more temperate fall. As autumn approaches, the chances of sunny days dip slightly, suggesting that if you're hoping for a bright September, it's best to make the most of those sporadic sunny spells while they last.

Percentage of Sunny Days in September in Hounslow

The chart illustrates the percentage of sunny days in Hounslow 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 Hounslow experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec19%25%29%49%33%28%38%25%29%25%32%17%
Data source: Hounslow September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hounslow in September

As summer gently fades into autumn, September in Hounslow, United Kingdom, offers a graceful transition with 12 hours of daylight. This marks a subtle decline from the sun-drenched days of July and August, where Hounslow basked in up to 16 hours of sunlight. However, the light is still plentiful, allowing for ample time to enjoy the early fall splendor. Following the peak of summer, daylight hours gradually diminish, hinting at the approaching winter months, where December's days shrink to just 7 hours. This trending pattern of longer days in the warmer months transitioning to shorter days as fall settles in sets the stage for the seasonal changes that define life in Hounslow.

Average Daylight Hours in Hounslow for September

The chart illustrates the variation in daylight duration in Hounslow throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 23m9h 58m11h 55m13h 54m15h 38m16h 32m16h 3m14h 30m12h 35m10h 36m8h 50m7h 53m
Data source: Hounslow daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hounslow

As September rolls into Hounslow, the average wind speed tends to dip to 3.3 m/s (7 mph), signaling a noticeable decrease compared to the bustling winds of earlier months. After experiencing a mild uptick during the summer, the autumn breeze becomes gentler, reminiscent of nature's transition into cooler temperatures. This shift is consistent with the pattern seen in the preceding months, where the winds peak during spring and early autumn before retreating into the softer, heartwarming gusts of winter. Embracing the essence of September, Hounslow welcomes a soothing, breezy atmosphere, inviting residents to enjoy the crisp air as they bid farewell to summer.

Average September Wind Speed in Hounslow

The chart displays monthly wind speed patterns in Hounslow, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.24.74.43.54.23.13.33.83.3 m/s4.43.84.4
Data source: Hounslow September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Hounslow Compares to Other Months

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

September and January present contrasting weather patterns, reflecting the transition from late summer to mid-winter. In September, the temperatures range from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), with an average of 15°C (59°F), offering a generally mild and pleasant climate. The month experiences about 45 mm (1.8 in) of precipitation over 10 days, accompanied by a relative humidity of 82%.

In contrast, January brings much colder temperatures, with a minimum of -5°C (24°F), an average of 5°C (41°F), and a maximum of 14°C (58°F). Precipitation increases to 54 mm (2.1 in) over the same number of days, and humidity rises slightly to 91%. For a more detailed look at January weather patterns, visit Hounslow weather in January.

September and February present distinctly different weather patterns. In September, temperatures range from a mild 4°C (39°F) at night to a warm 28°C (83°F) during the day, with an average of 15°C (59°F). The month sees about 45 mm (1.8 in) of precipitation, spread over roughly 10 days, and a comfortable humidity level of 82%. In contrast, February experiences much cooler temperatures, dipping as low as -5°C (23°F) at night and peaking at 18°C (65°F) during the day, with an average of 6°C (43°F). Precipitation increases to 53 mm (2.1 in) over approximately 11 days, and humidity rises slightly to 89%. For more specific details on February weather, you can visit Hounslow weather in February.

In September, weather in Hounslow tends to be milder, with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), offering a pleasant average of 15°C (59°F). The month sees around 45 mm (1.8 in) of precipitation over about 10 days, with humidity levels at 82%. In contrast, March brings cooler temperatures, with a minimum of -5°C (23°F) and a maximum of 22°C (71°F), leading to an average temperature of 7°C (46°F). The precipitation also increases slightly to 54 mm (2.1 in) over approximately 13 days, accompanied by a higher humidity level of 86%. For more specific details, you can check Hounslow weather in March.

September and April present distinct weather patterns, reflecting the transition from summer to autumn and winter to spring, respectively. In September, temperatures range from a cool 4°C (39°F) at night to a warm 28°C (83°F) during the day, with an average temperature of 15°C (59°F). The month sees an average of 45 mm (1.8 in) of precipitation over 10 days, with a humidity level of 82%. In contrast, April experiences cooler temperatures, with nightly lows dropping to -2°C (29°F) and daytime highs reaching up to 26°C (80°F), averaging at 10°C (49°F). It has slightly less rainfall, totaling 33 mm (1.3 in) across 8 days, and higher humidity at 85%. For more detailed insights into April weather specifically, visit Hounslow weather in April.

In September, the weather tends to be warmer on average, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F). The month sees an average temperature of 15°C (59°F) and experiences 45 mm (1.8 in) of precipitation over about 10 days, with humidity levels at 82%.

In contrast, May typically presents cooler conditions, with temperatures ranging from a minimum of 1°C (35°F) up to 25°C (78°F) and an average of 13°C (55°F). The month also experiences slightly higher rainfall, accumulating 62 mm (2.5 in) over approximately 11 days, while maintaining a slightly lower humidity at 79%.

For a more detailed look at the weather in May, you can check Hounslow weather in May.

In comparing the weather between September and June, several notable differences emerge. September tends to have a wider temperature range, with minimums dipping to 4°C (39°F) and maximums reaching 28°C (83°F), while June experiences milder conditions with minimums of 7°C (45°F) and maximums peaking at 31°C (89°F). June also sees slightly higher precipitation levels at 77 mm (3.0 in) over 9 days, compared to September's 45 mm (1.8 in) over 10 days. However, humidity levels are similar, with September at 82% and June at 80%. For more detailed insights on June’s weather, visit Hounslow weather in June.

When comparing the weather in September to that in July, we notice a significant drop in temperature and a change in overall conditions. September features a cooler temperature range with a minimum of 4°C (39°F) and an average of 15°C (59°F), while July boasts a warmer climate, with a minimum of 9°C (49°F) and an average of 18°C (65°F). Additionally, September experiences less rainfall, with 45 mm (1.8 in) over approximately 10 days, compared to July's higher precipitation of 64 mm (2.5 in) spread over 11 days. The humidity is notably higher in September at 82%, compared to July's 71%, indicating a more humid feel as summer transitions into autumn. For a more detailed look at July's climate, you can explore Hounslow weather in July.

In comparing the weather of September and August, September tends to be cooler and more temperate, with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F) and an average of 15°C (59°F). In contrast, August showcases warmer conditions, featuring temperatures that range from a minimum of 8°C (47°F) to a maximum of 34°C (93°F) with an average of 18°C (64°F). Additionally, September experiences slightly less precipitation at 45 mm (1.8 in) over 10 days, whereas August sees a higher total of 70 mm (2.7 in) across 12 days. Humidity levels are also higher in September at 82%, compared to August's 76%. For a detailed look at August's weather, see Hounslow weather in August.

In comparing the weather of September and October, we see a notable shift in temperature and precipitation patterns. September typically enjoys milder conditions with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), while October sees cooler temperatures with a minimum of 1°C (34°F) and a maximum of 22°C (73°F). Precipitation also increases in October, accumulating to 84 mm (3.3 in) over approximately 12 days, compared to September's 45 mm (1.8 in) over 10 days. Additionally, humidity levels rise in October to 90%, up from 82% in September, making the air feel distinctly more humid. For more detailed information, you can check Hounslow weather in October.

In September, the weather is generally milder with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), making it a pleasant month for outdoor activities. The total precipitation is 45 mm (1.8 in) over about 10 days, and humidity levels are relatively high at 82%. In contrast, November sees a significant dip in temperatures, with lows reaching down to -2°C (29°F) and highs averaging around 16°C (62°F). Although it tends to be slightly wetter, with 52 mm (2.0 in) of rain over 11 days, the humidity rises to 92%, creating a much chillier and damp atmosphere. For more detailed information, check out Hounslow weather in November.

In September, the weather is generally mild and variable, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), averaging around 15°C (59°F). It experiences about 45 mm (1.8 in) of precipitation over approximately 10 days, accompanied by a humidity level of 82%. In contrast, December brings a sharper chill, with temperatures dropping to a minimum of -4°C (24°F) and an average of 6°C (44°F), peaking at 14°C (58°F). The month is wetter, receiving 84 mm (3.3 in) of precipitation spread over 13 days and a higher humidity of 92%. For a more detailed look at December weather, please visit Hounslow weather in December.

Compare Hounslow's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hounslow

As summer fades into autumn, September in Hounslow brings a delightful transition in weather. The warmth of the early month is often felt, with temperatures reaching up to 28°C (83°F), but as days shorten, the cool air settles in, offering refreshing contrasts, particularly in the cooler nights that dip down to a brisk 4°C (39°F). Precipitation becomes more frequent, with about 10 days experiencing rain, leading to an average of 45 mm (1.8 in) over the month. This slight uptick in humidity at 82% adds a subtle mugginess that sets September apart from the drier months of summer. Overall, September serves as a unique blend of summer's remnants and autumn's arrival, making it a captivating time to observe the changing landscape. For more insights, explore the complete details at Hounslow Climate.