September Weather in Windsor, United Kingdom

Last updated: March 17, 2025

In September, Windsor, United Kingdom, experiences a transition into autumn with a maximum temperature reaching a pleasant 28°C (83°F), while the average settles at a mild 15°C (59°F). The month showcases a notable chill as temperatures dip to a minimum of 3°C (38°F) during the early mornings and late evenings. With precipitation totaling 45 mm (1.8 in) across 10 days, visitors can expect occasional rain, adding to the lush greenery characteristic of the region. Humidity is relatively high at 82%, making the air feel fresh. Whether exploring Windsor’s historic sites or enjoying the vibrant fall colors, September offers a unique charm wrapped in a blend of warm days and cooler nights.

September Temperature in Windsor

In September, Windsor experiences a delightful transition from the warmth of summer to the crispness of autumn. With nighttime temperatures dipping to a cool 3°C (38°F), the days offer a comfortable average of 15°C (59°F), allowing for pleasant outdoor activities. The maximum temperature can still reach up to 28°C (83°F), a gentle reminder of the lingering summer heat. This month marks a shift, as it bridges the hot highs of August, and hints at the cooler temperatures to come in October, making it an ideal time to enjoy the beauty of Windsor’s parks and gardens before the fall foliage truly sets in.

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

The chart illustrates September temperature patterns in Windsor, 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 Windsor 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 Windsor

In September, Windsor, United Kingdom, experiences moderate precipitation with an average of 45 mm (1.8 in) of rain over approximately 10 days. This marks a decrease compared to the more rain-soaked months of August and June, which see higher averages of 67 mm (2.6 in) and 74 mm (2.9 in) respectively. As summer transitions to autumn, September's rainfall, while lower, signals a shift in seasonal patterns, paving the way for a wetter October, noted for its 86 mm (3.4 in) of rain. This gradual shift reflects the typical climatic variations of Windsor, where the onset of autumn brings a distinct change in both temperature and precipitation trends.

September Precipitation Trends in Windsor

The chart displays monthly precipitation patterns in Windsor, 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.
JanFebMarAprMayJunJulAugSepOctNovDec525255336374646745865382
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Windsor

As summer transitions into autumn, September in Windsor, United Kingdom, experiences a notable shift in humidity levels. With an average of 82%, the month marks a slight increase from the drier summer months of July and August, which recorded 71% and 76%, respectively. This uptick reflects the onset of fall, characterized by cooler temperatures and a more substantial presence of moisture in the air. Interestingly, September's humidity is a precursor to the wetter months ahead, as the figures escalate significantly in October and remain high through the end of the year. This trend underscores the contrast between the refreshing early autumn and the impending dampness of winter.

September Average Humidity in Windsor

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

In September, Windsor experiences a UV Index of 6, placing it in the high exposure category with a burn time of just 25 minutes for fair-skinned individuals. This marks a slight decline from the peak values of July and August, which saw indices reaching 8, yet it remains significantly higher than the early months of the year, where the UV levels hovered around 1 to 4. As summer transitions into autumn, it's essential to stay vigilant about sun safety, even with the sun's rays softening. Keep in mind, if you're spending time outdoors, consider checking out the details at Windsor UV Index for up-to-date information.

Maximum UV Index Levels in Windsor for September

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

September in Windsor, United Kingdom, sees a delightful resurgence of sunshine, with approximately 300 hours of bright daylight. This month marks a transition from the peak summer months, where July boasts the highest sunshine at 404 hours, to the cooler autumn days ahead. After experiencing a slight decrease in sunlight during August, September offers a satisfying balance, providing enough sunlight for outdoor activities while hinting at the cozy autumn vibes to come. Compared to the comparatively dimmer months of November and December, with just 144 hours and 109 hours respectively, September is a precious window of warmth and brightness, inviting residents and visitors alike to soak in the last remnants of summer before fall settles in.

Monthly Sunshine Duration in Windsor: September Highlighted

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

Chance of Sun in Windsor During September

As summer fades and autumn approaches, September in Windsor, United Kingdom, brings a 28% chance of sunny weather. This figure shows a slight dip from the peak sunny days in April, which boasts a 50% chance, and mirrors the variability seen in summer months. While not the sunniest month, September maintains a moderate potential for sunny spells, especially compared to its counterparts like January and February, where sunshine is scarce. As the season transitions, residents and visitors can still hope for those cherished late-summer rays, though they might need to brace for the unpredictability of autumn weather.

Percentage of Sunny Days in September in Windsor

The chart illustrates the percentage of sunny days in Windsor 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 Windsor experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec20%25%29%50%33%27%38%24%28%26%32%17%
Data source: Windsor September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Windsor in September

As September arrives in Windsor, United Kingdom, the days begin to subtly shorten, with daylight lasting 12 hours. This marks a gentle transition from the long, sun-filled days of summer, which peaked in June and July with an impressive 16 hours of daylight. The gradual decline continues from August's 14 hours, hinting at the impending arrival of autumn. Following the vibrant energy of spring and summer months, September offers a balanced mix of light and darker evenings, paving the way for the cozy tones of fall. While daylight dwindles, the beauty of the changing seasons keeps Windsor’s charm alive, inviting both locals and visitors to enjoy the crisp air and vibrant foliage.

Average Daylight Hours in Windsor for September

The chart illustrates the variation in daylight duration in Windsor throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 24m9h 58m11h 55m13h 54m15h 38m16h 32m16h 3m14h 30m12h 35m10h 36m8h 50m7h 53m
Data source: Windsor daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Windsor

As summer gently fades, September in Windsor brings a tranquil shift in the air, characterized by an average wind speed of 3.3 m/s (7 mph). This represents a slight decrease from the breezier days of August and contrastingly, it foreshadows the gusty months ahead. With winds mellowing through late summer, residents can enjoy the serene transitions in their surroundings, making it a perfect time for leisurely strolls and outdoor activities. Notably, as the year progresses into October, we can anticipate a return to more dynamic winds, with speeds climbing back to 4.4 m/s (10 mph). Thus, September serves as a gentle reminder of the changing seasons, where the winds soften, inviting us to embrace the beauty of autumn.

Average September Wind Speed in Windsor

The chart displays monthly wind speed patterns in Windsor, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.34.84.43.54.33.23.33.83.3 m/s4.43.94.5
Data source: Windsor September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Windsor Compares to Other Months

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

September and January offer contrasting weather experiences. In September, temperatures range from a chilly 3°C (38°F) at night to a warm 28°C (83°F) during the day, with an average of 15°C (59°F). Although the month sees around 45 mm (1.8 in) of precipitation spread across 10 days, the humidity sits at a moderate 82%. In contrast, January presents a much colder climate, with temperatures dipping as low as -5°C (23°F) and peaking at 14°C (58°F), averaging just 5°C (41°F). Precipitation slightly increases to 52 mm (2.1 in) over 9 days, and humidity rises to 91%, creating a crisp, damp atmosphere. For a more detailed look at winter conditions, you can check Windsor weather in January.

September and February present contrasting weather patterns. September enjoys milder temperatures, with a minimum of 3°C (38°F) and an average of 15°C (59°F), peaking at 28°C (83°F). In contrast, February is much chillier, with temperatures ranging from a minimum of -5°C (23°F) to an average of 6°C (43°F), and a maximum of 18°C (65°F). While September sees 45 mm (1.8 in) of precipitation over about 10 days, February has slightly higher precipitation at 52 mm (2.0 in) within the same number of wet days. Additionally, February's humidity is higher at 89%, compared to September's 82%. For more detailed weather insights, explore Windsor weather in February.

September and March present quite contrasting weather conditions. In September, temperatures range from a minimum of 3°C (38°F) to a maximum of 28°C (83°F), with an average of 15°C (59°F). The month sees about 45 mm (1.8 in) of precipitation over approximately 10 days, with humidity at 82%. In contrast, March experiences cooler temperatures, with a minimum of -5°C (23°F), an average of 7°C (46°F), and a maximum reaching 22°C (71°F). This month has slightly higher precipitation at 55 mm (2.2 in) over around 13 days, and humidity levels are marginally higher at 86%. For a more detailed look at March weather, visit Windsor weather in March.

When comparing the weather in September and April, it's clear that both months offer distinct experiences. September typically has a milder temperature range, with a minimum of 3°C (38°F) and a maximum of 28°C (83°F), averaging at 15°C (59°F). This month also sees relatively higher precipitation with about 45 mm (1.8 in) falling over approximately 10 days, while humidity hovers around 82%. In contrast, April presents chillier conditions, with a minimum of -2°C (29°F) and a maximum reaching 26°C (80°F), averaging at a cooler 10°C (49°F). This month receives slightly less rain, totaling 33 mm (1.3 in) over around 8 days, and experiences marginally higher humidity at 85%. For a detailed look at this month’s climate, visit Windsor weather in April.

When comparing the weather in September and May, we notice several differences in temperature and precipitation. September generally boasts a wider temperature range, with minimums of 3°C (38°F) and maximums reaching 28°C (83°F), offering an average of 15°C (59°F). In contrast, May features slightly cooler temperatures, with a minimum of 1°C (35°F) and a maximum of 26°C (78°F), averaging 13°C (55°F). Precipitation in May is higher at 63 mm (2.5 in) over 10 days, compared to September’s 45 mm (1.8 in) during the same number of days. Humidity levels are also slightly higher in September at 82%, while May maintains a comfortable 79%. For a more detailed look at the weather specifics, check out Windsor weather in May.

In comparing the weather of September and June, we notice several differences. September presents a broader temperature range, with minimums dipping to 3°C (38°F) and maximums reaching 28°C (83°F), contributing to an average of 15°C (59°F). In contrast, June enjoys warmer temperatures, with minimums starting at 7°C (45°F) and reaching up to 31°C (88°F), leading to a slightly higher average of 16°C (62°F). Precipitation is also more prevalent in June, totaling 74 mm (2.9 in) over 9 days compared to September's 45 mm (1.8 in) across 10 days. Both months have relatively high humidity levels, with September at 82% and June at 80%. For a detailed look at how June weather specifically affects Windsor, you can visit Windsor weather in June.

When comparing the weather in September and July, notable differences emerge. September exhibits a broader temperature range, with minimums dropping to 3°C (38°F) and maximums reaching 28°C (83°F), resulting in a comfortable average of 15°C (59°F). In contrast, July tends to be warmer, with minimum temperatures around 9°C (48°F) and highs peaking at 35°C (96°F), leading to an average of 18°C (65°F). While both months experience precipitation, July records slightly more rainfall at 64 mm (2.5 in) over 11 days compared to September's 45 mm (1.8 in) over 10 days. Additionally, September shows higher humidity at 82% compared to July's 71%, contributing to a different overall feel in the air. For more detailed insights into July's weather, check Windsor weather in July.

When comparing the weather of September to August, a noticeable shift in temperature and humidity emerges. September experiences a wider temperature range, with minimums dropping to 3°C (38°F) and maximums reaching up to 28°C (83°F), whereas August offers milder conditions, ranging from 8°C (46°F) to a peak of 33°C (92°F). Precipitation is also less in September, totaling 45 mm (1.8 in) over about 10 days, compared to August's 67 mm (2.6 in) over 12 days. Furthermore, September's humidity is slightly higher at 82% compared to August's 76%. For more detailed weather insights, visit Windsor weather in August.

September's weather offers a warm transition from summer, with average temperatures around 15°C (59°F) and highs reaching up to 28°C (83°F). The month experiences modest rainfall of 45 mm (1.8 in) over about 10 days, accompanied by an average humidity of 82%. In contrast, October ushers in cooler conditions, with average temperatures dropping to 12°C (53°F) and maximums peaking at 23°C (73°F). The amount of rainfall nearly doubles to 86 mm (3.4 in) over 12 days, and the humidity rises slightly to 90%. For detailed insights into October's climate, check out this link: Windsor weather in October.

In September, temperatures range from a mild 3°C (38°F) at night to a warm 28°C (83°F) during the day, with an average of 15°C (59°F). The month sees around 45 mm (1.8 in) of precipitation over approximately 10 days, alongside relatively high humidity of 82%. In contrast, November brings cooler conditions, with temperatures dropping to a minimum of -2°C (29°F) and an average of 8°C (47°F), peaking at 16°C (62°F). The month experiences slightly more rainfall, totaling 53 mm (2.1 in) over 11 days of precipitation, and even higher humidity at 92%. For more details on November weather, check Windsor weather in November.

In September, the weather is generally milder, with temperatures ranging from a minimum of 3°C (38°F) to a maximum of 28°C (83°F) and an average of 15°C (59°F). This month experiences 45 mm (1.8 in) of precipitation over about 10 days, coupled with a humidity level of 82%. In contrast, December brings cooler conditions, where temperatures drop to a minimum of -4°C (24°F) and peak at 14°C (58°F), resulting in an average temperature of 6°C (44°F). December also sees a higher precipitation level of 82 mm (3.2 in) spread over approximately 14 days and increased humidity at 92%. For more detailed insights on weather conditions, you can check Windsor weather in December.

Compare Windsor's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Windsor

As summer fades, September in Windsor ushers in a notable shift in weather, with temperatures cooling down from the sweltering heat of the previous months. The average temperature dips to a moderate 15°C (59°F), offering a refreshing respite, while occasional warm days can still reach up to 28°C (83°F). In contrast to the drier summer months, expect more rain, with up to 45 mm (1.8 in) falling over approximately 10 days. The humidity also rises, often reaching 82%, presenting a more autumnal feel as the leaves begin to change. This transitional period sets the stage for the charming beauty of Windsor as it prepares for fall. For more detailed insights, check out Windsor Climate.