September Weather in Perth, United Kingdom

Last updated: March 17, 2025

September in Perth, United Kingdom is a month of transition, where summer gives way to the cool embrace of autumn. Temperatures can reach a pleasant maximum of 25°C (77°F), while the average hovers around 12°C (54°F), dipping to a brisk minimum of -1°C (30°F) during the nights. This month is characterized by 77 mm (3.0 in) of precipitation, occurring over 14 rainy days, contributing to the region's lush greenery. With humidity levels soaring to 90%, the air can feel quite damp, making it a quintessentially British experience. As the days grow shorter, locals and visitors alike can enjoy the changing landscape, whether it's through morning mist or the splashes of color from autumn leaves.

September Temperature in Perth

In September, Perth experiences a notable shift as summer wanes, with temperatures ranging from a brisk -1°C (30°F) at night to a pleasant 25°C (77°F) during the day. The average temperature sits comfortably at 12°C (54°F), making it a transitional month where the warmth of late summer lingers but starts to hint at the chill of autumn ahead. This month’s climate reflects a gradual cooling trend compared to the peak warmth of August, but still offers ample opportunity for outdoor activities under sunny skies. As the days grow shorter and temperatures cool slightly, September presents a perfect blend of comfortable warmth and the scenic beauty of early fall.

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

The chart illustrates September temperature patterns in Perth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec383941455056595854484339
Data source: Temperature data for Perth generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Perth

September in Perth, United Kingdom, brings an average precipitation of 77 mm (3.0 in) over approximately 14 days, marking a transition toward the wetter autumn months ahead. As summer fades, the rainfall begins to pick up following a relatively dry April and a mild May, with September's totals sitting comfortably between the heavier months of August and October, which see 107 mm (4.2 in) and 109 mm (4.3 in) respectively. This trend highlights the gradual buildup of moisture in the atmosphere, setting the stage for the more sustained rains typical of the fall season. Overall, September’s rainfall reflects the shifting patterns of weather as the region moves from summer warmth into the embrace of autumn.

September Precipitation Trends in Perth

The chart displays monthly precipitation patterns in Perth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec591119040748286107771099594
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Perth

As summer transitions to autumn, September in Perth, United Kingdom, experiences a notable surge in humidity, reaching 90%. This marks a slight increase from the preceding months, with humidity levels consistently hovering in the mid-eighties throughout the summer. Interestingly, this uptick signifies a shift as the year progresses towards its wetter season, with October and November expected to peak even higher at 91% and 92%, respectively. Overall, September sets the stage for this seasonal change, showcasing a drier summer giving way to the dampness of fall.

September Average Humidity in Perth

This chart illustrates the average monthly humidity levels in Perth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec89%88%86%84%82%84%86%86%90%91%92%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Perth

As September rolls into Perth, United Kingdom, the UV Index settles at a moderate level of 5, indicating a safe but watchful approach to sun exposure. This month reflects a gradual shift from the higher indices of late summer, notably peaking at 6 in both July and August. With a burn time of 30 minutes, residents should still take precautions when spending time outdoors, especially during peak sunlight hours. The trend reveals that while UV levels are decreasing, they remain significant enough to warrant awareness and protection. To stay informed about the sun's intensity and make the most of your time outside, check out the detailed data on the Perth UV Index.

Maximum UV Index Levels in Perth for September

The chart shows the monthly maximum UV Index (UVI) for Perth 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.
JanFebMarAprMayJunJulAugSepOctNovDec123568765311
Data source: Perth 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 Perth

September in Perth, United Kingdom, offers a delightful transition into autumn, characterized by 264 hours of sunshine. While the month sees a noticeable decrease in sunshine compared to the bustling summer peak of 373 hours in May, it still stands as a significant month for light as it edges towards the cooler seasons. The gradual decline in daylight from the vibrant summer months reflects a change in nature and mood, yet September retains a golden glow that invites outdoor activities and exploration. As daylight slips away through October and into the winter months, punctuated by dramatic falls to just 92 hours of sunshine in November, September serves as a gentle reminder of the lingering warmth and brightness before the darker days settle in.

Monthly Sunshine Duration in Perth: September Highlighted

The September sunshine duration represents the total number of hours Perth 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.
JanFebMarAprMayJunJulAugSepOctNovDec67h112h174h310h373h358h371h329h264h187h92h64h
Data source: Perth September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Perth During September

When it comes to September, the likelihood of experiencing sunny weather in Perth, United Kingdom, dips to a modest 18%. This marks one of the lowest probabilities of sunshine for the year, closely mirroring the outlook in October. As summer transitions into autumn, the chances of clear skies diminish, showing a notable contrast to the more favorable daylight and sunshine percentages seen in April and November, where the averages hit 45% and 29% respectively. Overall, while September may bring a hint of pleasant weather, it's fair to say that those hoping for a sun-soaked month might need to manage their expectations.

Percentage of Sunny Days in September in Perth

The chart illustrates the percentage of sunny days in Perth 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 Perth experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec28%23%20%45%22%21%24%23%18%18%29%19%
Data source: Perth September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Perth in September

As the vibrant summer season gives way to the crispness of autumn, September in Perth, United Kingdom, offers a delightful mix of changing daylight, with an average of 12 hours of daylight. This marks a slight decrease from the sun-soaked months of June and July, which enjoyed the longest days of up to 17 hours. Trending towards shorter days, September still retains a generous amount of sunlight compared to the darker winter months, where daylight dwindles to just 6 hours in December. Notably, the gradual transition from the more sun-intensive May and June begins to usher in the cozy ambiance of fall, showcasing the dynamic interplay of light that characterizes Perth's yearly cycle.

Average Daylight Hours in Perth for September

The chart illustrates the variation in daylight duration in Perth throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 34m9h 32m11h 53m14h 17m16h 27m17h 38m16h 59m15h 1m12h 41m10h 18m8h 7m6h 54m
Data source: Perth daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Perth

In September, Perth, UK, experiences a gentle breeze with an average wind speed of 2.6 m/s (6 mph), reflecting a slight uptick following the quieter summer months. As autumn approaches, the winds begin to pick up, hinting at the transitional weather patterns ahead. This month’s speed is consistent with the lighter winds seen earlier in the year, particularly in July and August, where the calmest conditions prevail. However, as October rolls in, Perth typically welcomes stronger gusts, making September a serene interlude before the bluster of autumn truly sets in. Overall, the data reveals a seasonal rhythm, where September acts as a delicate bridge between the stillness of summer and the energetic winds of fall.

Average September Wind Speed in Perth

The chart displays monthly wind speed patterns in Perth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.74.33.72.62.83.12.02.22.6 m/s3.43.82.9
Data source: Perth September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Perth Compares to Other Months

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

September and January exhibit distinct weather patterns, marking a significant shift in climate as the year progresses. In September, temperatures range from a chilly minimum of -1°C (30°F) to a pleasant maximum of 25°C (77°F), with an average of 12°C (54°F). This month also experiences higher precipitation, totaling 77 mm (3.0 in) over 14 days and features a humidity level of 90%.

In contrast, January is colder, with minimum temperatures dropping to -6°C (21°F) and a maximum of 13°C (55°F), resulting in an average temperature of 3°C (38°F). Although January sees less rainfall at 59 mm (2.3 in) over 10 days, the humidity remains high at 89%. For further details, you can check Perth weather in January.

When comparing the weather in September and February, notable differences emerge. September experiences milder temperatures, ranging from a minimum of -1°C (30°F) to a maximum of 25°C (77°F), with an average temperature of 12°C (54°F). Humidity is relatively high at 90%, and the month sees about 77 mm (3.0 in) of precipitation over 14 days. In contrast, February is significantly colder, with temperatures ranging from -14°C (7°F) to a maximum of 14°C (58°F) and an average of 4°C (39°F). Precipitation increases to 111 mm (4.4 in), spread over 16 days, and humidity remains slightly lower at 88%. For more detailed information, you can explore Perth weather in February.

When comparing the weather in September and March, notable differences emerge. September experiences milder temperatures, with averages around 12°C (54°F) and maximums reaching 25°C (77°F), while March's temperatures are cooler, averaging only 5°C (41°F) and peaking at 17°C (62°F). Precipitation levels are somewhat higher in March, totaling 90 mm (3.5 in) over 16 days, compared to September's 77 mm (3.0 in) across 14 days. Humidity remains relatively high in both months, at 90% in September and 86% in March, contributing to a damp feel, particularly during the transitional spring month. For more detailed insights, check out Perth weather in March.

September generally experiences milder temperatures with an average of 12°C (54°F) and a maximum of 25°C (77°F), while April is cooler, with an average of 7°C (45°F) and a maximum of 21°C (69°F). The humidity is slightly higher in September at 90% compared to April's 84%, making September feel a bit more humid. Additionally, September sees more precipitation overall, with 77 mm (3.0 in) over 14 days, in contrast to April's 40 mm (1.6 in) over 10 days. For more detailed insights into April weather, you can visit Perth weather in April.

September and May showcase a striking similarity in temperature, with both months reaching a maximum of 25°C (77°F). However, September boasts a slightly warmer average temperature of 12°C (54°F) compared to May's 10°C (51°F). In terms of precipitation, September experiences a bit more rain at 77 mm (3.0 in) over 14 days, while May sees 74 mm (2.9 in) across 13 days. Additionally, September is characterized by higher humidity levels at 90%, compared to May's 82%, resulting in a more humid atmosphere. For a deeper dive into what to expect, you can check out Perth weather in May.

September weather features a broader temperature range with minimums dipping to -1°C (30°F) and maximums reaching 25°C (77°F), while the average sits at 12°C (54°F). In contrast, June is typically milder, with minimums of 3°C (37°F) and maximums of 28°C (83°F), averaging 13°C (56°F). Both months experience significant precipitation, with September seeing 77 mm over 14 days and June slightly higher at 82 mm over 15 days. Humidity levels are higher in September at 90%, compared to June's 84%. For more details on June weather, visit Perth weather in June.

In comparing the weather of September and July, we notice distinct differences. September has a broader temperature range, with a minimum of -1°C (30°F) and a maximum of 25°C (77°F), giving it an average temperature of 12°C (54°F). Meanwhile, July maintains a milder range, with a minimum of 5°C (42°F) and an average of 15°C (59°F), peaking at the same maximum of 25°C (78°F) as September. In terms of precipitation, July experiences slightly more rain at 86 mm (3.4 in) over 15 days compared to September's 77 mm (3.0 in) across 14 days. Humidity levels are also quite high, with September at 90% and July a bit lower at 86%. For a closer look at weather patterns during July in Perth, you can visit Perth weather in July.

In comparing the weather between September and August, September experiences a notable drop in minimum temperatures, with lows reaching -1°C (30°F) compared to August's milder 4°C (40°F). Despite both months achieving a maximum temperature of 25°C (77°F), the average temperature in September is lower at 12°C (54°F) versus 14°C (58°F) in August. Precipitation is also more frequent in August, totaling 107 mm (4.2 in) over 16 days, compared to September's 77 mm (3.0 in) over 14 days. However, September boasts slightly higher humidity at 90% compared to August’s 86%. For more detailed information on August weather, you can visit Perth weather in August.

September and October exhibit notable differences in weather patterns. In September, temperatures range from a minimum of -1°C (30°F) to a maximum of 25°C (77°F), with an average of 12°C (54°F). The month experiences around 77 mm (3.0 in) of precipitation over 14 days, accompanied by high humidity at 90%. In contrast, October brings cooler temperatures, with a minimum of -2°C (28°F), an average of 9°C (48°F), and a maximum of 17°C (63°F). Precipitation increases to 109 mm (4.3 in) across 16 days, and humidity remains slightly higher at 91%. For a detailed look at October weather specifics, check out Perth weather in October.

In comparing the weather between September and November, September tends to be milder, with average temperatures around 12°C (54°F) and maximums reaching up to 25°C (77°F). It also experiences a higher frequency of pleasant days, with an average of 14 days of precipitation totaling 77 mm (3.0 in). In contrast, November brings cooler temperatures, with an average of 6°C (43°F) and maximums capping at 14°C (57°F). It also sees slightly increased rainfall, totaling 95 mm (3.8 in) over 15 days, contributing to a noticeably chillier and wetter atmosphere. For more detailed insights, you can check Perth weather in November.

The weather in September is generally milder than in December, with temperatures ranging from a minimum of -1°C (30°F) to a maximum of 25°C (77°F), and an average of 12°C (54°F). In contrast, December brings colder conditions, with minimum temperatures dropping to -7°C (19°F) and maximums peaking at 12°C (54°F), resulting in a chilly average of 4°C (39°F). Both months experience significant precipitation, with September recording 77 mm (3.0 in) over 14 days and December seeing even higher totals of 94 mm (3.7 in) across 15 days. Humidity levels are also relatively high in both months, at 90% for September and slightly lower at 88% for December. For more detailed insights into December weather, visit Perth weather in December.

Compare Perth's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Perth

As September unfolds in Perth, the weather begins to shift noticeably, marking a transition from the chill of winter to the warm embrace of spring. With temperatures reaching a pleasant maximum of 25°C (77°F) during the day and cooling down to an average of 12°C (54°F) at night, this month sees a delightful warmth that sets it apart from the cooler preceding months. However, it's not all sunshine, as September also brings its fair share of rain, with 77 mm of precipitation spread over about 14 days, creating a humid atmosphere that can sometimes feel heavy. This unique blend of warmth and moisture makes September a season of vivid blooms and lush landscapes, perfectly capturing the essence of Perth's climate as the city emerges from winter's grip. For a comprehensive view of what to expect throughout the year, visit Perth Climate.