September Weather in Horsham, United Kingdom

Last updated: March 17, 2025

Experience the charm of September in Horsham, United Kingdom, where temperatures fluctuate from a mild 3°C (37°F) to a delightful 27°C (81°F). On average, the month sees a comfortable 15°C (60°F), making it a pleasant time for outdoor activities. However, be prepared for some rain, as the area receives approximately 50 mm (2.0 in) of precipitation over 9 days, contributing to an 82% humidity level that enhances the lush, green scenery. Whether you're exploring the vibrant town or enjoying the surrounding countryside, September in Horsham offers a refreshing blend of warmth and occasional showers.

September Temperature in Horsham

September in Horsham, United Kingdom heralds the onset of autumn with a noticeable shift in temperatures. The month typically begins with a minimum of 3°C (37°F), gradually warming to an inviting 27°C (81°F) during the day, making it a transitional period filled with mild and enjoyable weather. With an average temperature hovering around 15°C (60°F), September offers a pleasant escape from the summer heat, reminiscent of late summer vibes yet tinged with the crispness of fall. As the month progresses, cooler nights signal the approaching winter, suggesting that while the warmth lingers, the vibrant colors of autumn are just around the corner. This blend of mild days and cooler evenings creates the perfect backdrop for enjoying the changing seasons in Horsham.

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

The chart illustrates September temperature patterns in Horsham, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec414346495561646359544744
Data source: Temperature data for Horsham 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 Horsham

In September, Horsham experiences a moderate precipitation level of 50 mm (2.0 in) across approximately 9 days, offering a transition between the summer months and the impending autumn. This amount is slightly below the preceding August's 67 mm (2.6 in), reflecting a gradual decline as the region shifts towards drier autumn weather. Interestingly, while September sees a decrease in rain volume, it maintains a consistent rhythm of wet days that is characteristic of late summer and early fall. As the year progresses into October, precipitation levels are expected to surge again, with 91 mm (3.6 in) anticipated, signaling the onset of wetter weather.

September Precipitation Trends in Horsham

The chart displays monthly precipitation patterns in Horsham, 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.
JanFebMarAprMayJunJulAugSepOctNovDec545757346271576750916597
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Horsham

In September, Horsham experiences a noticeable shift in humidity, with levels averaging 82%. This marks a subtle increase from the drier summer months, where July and August recorded 71% and 76%, respectively. As the transition into autumn begins, the humidity steadily climbs, nearing the levels seen in the early months of the year. This seasonal pattern highlights Horsham's characteristic dampness, with October and November following suit at 90% and 92%, respectively. Overall, the trend reveals a gradual return to the high humidity typical of Horsham's winter months, creating a crisp yet moist atmosphere as the leaves start to change.

September Average Humidity in Horsham

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

As September unfolds in Horsham, the UV Index reflects a high level of sun exposure, sitting at 6 and indicating a potential burn time of 25 minutes for unprotected skin. This trend marks a slight decrease from the peak levels of summer, where both June and July reached a very high index of 8. Nevertheless, it’s essential to remain cautious, as the high exposure category means that sun safety should still be a priority. As autumn approaches, the UV Index will gradually decline, leading into October's moderate levels. For those interested in more detailed information regarding UV exposure throughout the year, visit Horsham UV Index.

Maximum UV Index Levels in Horsham for September

The chart shows the monthly maximum UV Index (UVI) for Horsham 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.
JanFebMarAprMayJunJulAugSepOctNovDec124678876421
Data source: Horsham 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 Horsham

As summer transitions into autumn, September in Horsham, United Kingdom, shines brightly with 309 hours of sunshine, marking a delightful end to the warmer months. After a seasonal peak in July with 408 hours of light, the sunlight begins to taper but remains significantly more abundant than the winter months. This trend illustrates a gradual decline from peak summer days, transitioning into the cozy ambiance of early fall. With September’s sunshine outshining the gray beginnings of autumn, it offers a perfect opportunity to enjoy the changing colors of nature before the chill sets in. In the broader context, the steady increase from January’s mere 99 hours to September’s bounty reflects the vibrancy of the British seasons, making each warm hour all the more cherished.

Monthly Sunshine Duration in Horsham: September Highlighted

The September sunshine duration represents the total number of hours Horsham 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.
JanFebMarAprMayJunJulAugSepOctNovDec99h148h209h326h405h396h408h375h309h244h149h112h
Data source: Horsham September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Horsham During September

In Horsham, the likelihood of sunny weather shows an intriguing trend as the seasons shift. September enjoys a 33% chance of sunshine, highlighting a modest yet significant improvement compared to the dreariness of winter months, where January languishes at just 22%. While the peak of sunny days occurs in April at 55%, September remains relatively bright, outpacing the summer months of June and August, which feature 30% and 32% likelihoods respectively. This gradual transition from the vibrant days of summer to the cooler autumn heralds a season of changing leaves, with the sun still making a lively appearance to brighten early autumn days in Horsham.

Percentage of Sunny Days in September in Horsham

The chart illustrates the percentage of sunny days in Horsham 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 Horsham experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec22%26%37%55%38%30%40%32%34%28%35%20%
Data source: Horsham September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Horsham in September

As September graces Horsham, daylight begins to wane, with the month offering about 12 hours of light each day. This marks a gentle decline from the sun-soaked summer months of June and July, which basked in 16 and 15 hours of daylight, respectively. Following the vibrant growth of spring and summer, September signifies a transition, as days become progressively shorter and nature prepares for the quieter tones of autumn. While the sun still casts a generous glow, the gradual decrease in daylight serves as a reminder of the cycle of seasons, culminating in the cozy, introspective months ahead. As we savor these lingering sunny days, it becomes clear that September is both a farewell to summer and a welcoming embrace of the autumnal shift.

Average Daylight Hours in Horsham for September

The chart illustrates the variation in daylight duration in Horsham throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 28m10h11h 55m13h 52m15h 34m16h 27m15h 59m14h 27m12h 34m10h 38m8h 53m7h 58m
Data source: Horsham daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Horsham

As summer transitions into autumn, the September wind in Horsham gently calms, averaging 3.6 m/s (8 mph), making it one of the quieter months of the year. This decline follows the relatively brisk winds of the late summer, which peaked at 4.2 m/s (9 mph) in August. Interestingly, after a steady march of modest winds through spring, the early fall breeze sets a more tranquil tone as nature begins its seasonal shift. The winds are expected to pick up again in October, reaching an average of 4.9 m/s (11 mph), but for now, September invites moments of stillness and reflection amidst the slowly changing leaves.

Average September Wind Speed in Horsham

The chart displays monthly wind speed patterns in Horsham, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.85.34.83.84.83.23.74.23.6 m/s4.94.04.9
Data source: Horsham September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Horsham Compares to Other Months

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

September weather is characterized by milder temperatures, with a minimum of 3°C (37°F) and an average of 15°C (60°F), peaking at a comfortable 27°C (81°F). The month sees about 50 mm (2.0 in) of precipitation over approximately 9 days, accompanied by a humidity level of 82%. In contrast, January experiences much colder conditions, with temperatures dropping to a minimum of -4°C (24°F) and an average of just 5°C (42°F), while the maximum reaches only 14°C (57°F). Precipitation increases slightly to 54 mm (2.1 in) over about 10 days, coupled with higher humidity at 91%. For more detailed insights into January weather, you can visit Horsham weather in January.

September and February display distinct differences in weather patterns. In September, temperatures range from a mild minimum of 3°C (37°F) to a comfortable maximum of 27°C (81°F), with an average of 15°C (60°F). The month typically experiences about 50 mm (2.0 in) of precipitation over 9 days, accompanied by a relatively high humidity of 82%. In contrast, February is marked by colder temperatures, with a minimum of -5°C (23°F) and a maximum of 16°C (62°F), averaging around 6°C (44°F). This month sees slightly more precipitation at 57 mm (2.2 in) over 11 days, and humidity increases to 89%. For a deeper dive into February conditions, check out Horsham weather in February.

In comparing the weather of September and March, we see notable differences in temperature and conditions. September tends to be warmer, with average temperatures reaching up to 15°C (60°F) and a maximum of 27°C (81°F), while March's average sits lower at 8°C (46°F) and peaks at 19°C (67°F). Additionally, March experiences slightly higher precipitation at 57 mm (2.2 in) over 13 days compared to September's 50 mm (2.0 in) over 9 days. Humidity levels are also slightly elevated in March at 86%, compared to September's 82%. For a more detailed look at March weather, you can visit Horsham weather in March.

September and April present quite different weather patterns. In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 27°C (81°F), with an average of 15°C (60°F). The month experiences about 50 mm (2.0 in) of precipitation across 9 days, and the humidity is relatively high at 82%. In contrast, April typically has cooler temperatures, ranging from a minimum of -2°C (29°F) to a maximum of 23°C (73°F), with an average of 10°C (49°F). This month sees less precipitation, with 34 mm (1.3 in) across 8 days, and slightly higher humidity at 85%. For more detailed insights on April weather, you can check Horsham weather in April.

September and May exhibit notable differences in weather patterns. In September, temperatures range from a chilly 3°C (37°F) to a warm 27°C (81°F), with an average of 15°C (60°F). The month sees an average of 50 mm (2.0 in) of precipitation across about 9 days, with humidity levels at 82%. Conversely, May tends to be slightly cooler overall, with temperatures ranging from 1°C (34°F) to 25°C (77°F), averaging 13°C (55°F). The rainfall in May is slightly higher at 62 mm (2.4 in) over 11 days, with humidity hovering around 79%. Overall, while both months display mild weather, September is generally warmer and more humid than May. For more detailed information, check out Horsham weather in May.

In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 27°C (81°F), with an average of 15°C (60°F), while June experiences slightly warmer conditions, with temperatures ranging from 7°C (45°F) to 30°C (86°F) and an average of 16°C (61°F). Additionally, September sees around 50 mm (2.0 in) of rainfall over 9 days, whereas June has slightly higher precipitation, totaling 71 mm (2.8 in) across 8 days. Humidity levels are also comparable, with September at 82% and June slightly lower at 80%. For a detailed overview of the June weather, you can check Horsham weather in June.

In July, the weather tends to be warmer, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 33°C (92°F), creating a lively summer atmosphere. The humidity is relatively lower at 71%, making the heat more bearable, but precipitation occurs on about 11 days, totaling 57 mm (2.2 in). In contrast, September is cooler, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 27°C (81°F) and an average of 15°C (60°F). Although September experiences slightly less rainfall at 50 mm (2.0 in) over 9 days, the humidity level is higher at 82%, giving it a more damp feel. For more detailed information on July weather, you can visit Horsham weather in July.

In comparing the weather between September and August, September tends to be cooler, with average temperatures ranging from a minimum of 3°C (37°F) to a maximum of 27°C (81°F), whereas August experiences warmer conditions, featuring a minimum of 8°C (47°F) and a maximum of 32°C (89°F). Additionally, September receives slightly less precipitation, totaling 50 mm (2.0 in) over 9 days, compared to August, which sees 67 mm (2.6 in) over 11 days. Humidity levels are higher in September at 82%, compared to 76% in August, contributing to a more subdued, yet still comfortable, end-of-summer atmosphere. For more details on the weather in August, you can check Horsham weather in August.

In comparing the weather between September and October, we see a notable shift in temperatures and precipitation levels. September experiences a broader temperature range, with a minimum of 3°C (37°F) and a maximum of 27°C (81°F), resulting in a comfortable average of 15°C (60°F). In contrast, October sees cooler temperatures, with a minimum of 2°C (36°F) and an average of 12°C (54°F), peaking at 21°C (70°F). Additionally, October is noticeably wetter, with 91 mm (3.6 in) of precipitation spread over 14 days compared to September's 50 mm (2.0 in) over just 9 days. The humidity also rises in October to 90%, compared to September's 82%. For more detailed insights, check out Horsham weather in October.

September typically offers milder weather with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 27°C (81°F) and an average temperature of 15°C (60°F). In contrast, November sees cooler temperatures, where the minimum drops to -2°C (29°F) and the average temperature decreases to 8°C (47°F), with a maximum of 16°C (62°F). While September generally experiences around 50 mm (2.0 in) of precipitation over 9 days, November has a slightly higher precipitation of 65 mm (2.6 in) across 12 days, coupled with increased humidity of 92% compared to 82% in September. For more specific details, you can visit Horsham weather in November.

September and December present distinctly different weather patterns. In September, temperatures range from a mild 3°C (37°F) to a comfortable maximum of 27°C (81°F), with an average of 15°C (60°F). The month sees about 50 mm (2.0 in) of precipitation over approximately 9 days, accompanied by relatively high humidity at 82%. In contrast, December experiences colder temperatures, ranging from a low of -3°C (26°F) to a high of 14°C (58°F), with an average of 7°C (45°F). Precipitation triples to 97 mm (3.8 in) and occurs over 15 days, while humidity increases to 92%. For more details, visit Horsham weather in December.

Compare Horsham's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Horsham

As September rolls in, Horsham experiences a delightful transition into the cooler months, offering a refreshing change from the summer heat. With an average temperature of about 15°C (60°F), it’s significantly cooler than the peak summer months, accompanied by occasional rainfall that totals around 50 mm across about nine days. The humidity level remains relatively high at 82%, adding to the crispness in the air. This blend of warm days and cooler nights makes September a vibrant time to witness the onset of autumn, characterized by colorful foliage and a more temperate climate. For a more detailed look at Horsham's weather patterns throughout the year, visit Horsham Climate.