September Weather in Mount Isa, Australia

Last updated: February 25, 2025

In September, Mount Isa experiences a striking climate characterized by maximum temperatures soaring to 39°C (102°F), while the average temperature settles at a comfortable 24°C (75°F). Nights can be cool, with minimum temperatures dropping to 9°C (48°F). This month typically sees minimal rainfall, with an average precipitation amount of just 5 mm (0.2 in) over an average of only one rainy day. Relative humidity remains low at 32%, making September a warm and inviting time to enjoy the stunning landscapes of this iconic Australian town.

September Temperature in Mount Isa

As September arrives in Mount Isa, Australia, temperatures start to embrace the warmth of the approaching spring. Average daytime highs can reach a sizzling 39°C (102°F), while nighttime lows settle at a more comfortable 9°C (48°F). This month sees a pleasant midpoint in temperature, with averages hovering around 24°C (75°F). Compared to the previous winter months, where lows dipped to single digits, September marks a shift towards more moderate weather, paving the way for the hotter months ahead. The gradual increase in warmth is evident, hinting at the vibrant outdoor activities that this lively region has to offer as it transitions from winter chill to the embrace of summer heat.

September Weather in Mount Isa: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Mount Isa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec888584797064646775828590
Data source: Temperature data for Mount Isa 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 Mount Isa

In September, Mount Isa experiences a slight uptick in precipitation, with recorded rainfall of 5 mm (0.2 in) over just 1 day. This marks a modest recovery after a notably dry August, where no rain fell at all. The month sits on the cusp of the wet season, hinting at the transition with a small bounty of moisture. With precipitation steadily increasing from the parched winter months, September paves the way for the more significant rainfall expected in the coming months, particularly as October and November bring nearly double the precipitation seen this month. As the year progresses, the patterns become increasingly favorable for replenishing local water sources, showcasing the dynamic climate of this vibrant Australian region.

September Precipitation Trends in Mount Isa

The chart displays monthly precipitation patterns in Mount Isa, 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.
JanFebMarAprMayJunJulAugSepOctNovDec558587116105101820
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Mount Isa

In September, Mount Isa experiences a significant drop in humidity, recorded at a mere 32%. This marks a noticeable decline from the previous month, creating a particularly dry atmosphere that contrasts sharply with the peak of early summer, where humidity levels soar to 62% in February. Following September, humidity levels continue to decrease, reaching their lowest point in October at just 23%. This trend demonstrates a clear transition into the drier months, emphasizing the stark climatic shifts in Mount Isa as the year progresses. Residents and visitors alike can expect a crisp, invigorating atmosphere at this time, perfect for outdoor activities.

September Average Humidity in Mount Isa

This chart illustrates the average monthly humidity levels in Mount Isa, 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.
JanFebMarAprMayJunJulAugSepOctNovDec56%62%71%53%47%47%42%43%33%23%28%47%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Mount Isa

In September, Mount Isa experiences an UV Index of 13, categorized as extreme, with a burn time of just 10 minutes. This marks a slight increase from the previous month's UV Index of 11. As the year progresses, the UV Index trends suggest a generally high level of sun exposure, particularly in the first half of the year, showcasing values ranging from 9 to a staggering 17 in January. The transition into spring sees a gradual rise in UV levels, peaking again in October with an index of 14. With such intense sunlight, it's crucial for residents and visitors to be aware of the potential for sunburn and take appropriate precautions. For more details on UV levels throughout the year, visit Mount Isa UV Index.

Maximum UV Index Levels in Mount Isa for September

The chart shows the monthly maximum UV Index (UVI) for Mount Isa 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.
JanFebMarAprMayJunJulAugSepOctNovDec171615129781113141616
Data source: Mount Isa 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 Mount Isa

As the chill of winter fades, September brings a delightful embrace of sunshine to Mount Isa, Australia, with an impressive 314 hours of sun-soaked days. This month marks a significant peak in the year, following August's already generous 308 hours. The trend is unmistakable: each month, the hours of sunshine steadily increase, culminating in the brilliant brightness of spring. With October promising an even greater 330 hours, residents and visitors alike can indulge in the beauty of the landscape bathed in sunlight, forging vibrant experiences under the vast, blue sky. This seasonal transition not only enhances the natural beauty but also energizes the spirit of the community, setting the stage for a radiant end to the year.

Monthly Sunshine Duration in Mount Isa: September Highlighted

The September sunshine duration represents the total number of hours Mount Isa 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.
JanFebMarAprMayJunJulAugSepOctNovDec269h284h305h298h289h276h293h308h314h330h329h342h
Data source: Mount Isa September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Mount Isa During September

As September arrives in Mount Isa, the chance of sunny weather remains a promising 79%, reflecting the tail end of the dry winter months. The trend in sunshine is notable, with the region gradually transitioning from the highs of August, which boasts a striking 90% chance of sun, to the slightly cooler days of October, where the likelihood dips to 70%. This makes September an excellent time for outdoor activities, as the sun still dominates the skies, maintaining a bright and warm ambiance that perfectly complements the blooming spring season. Despite a decrease from the peak summer months, the sun still plays a significant role, ensuring ample opportunities to soak in the splendid Australian landscape.

Percentage of Sunny Days in September in Mount Isa

The chart illustrates the percentage of sunny days in Mount Isa 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 Mount Isa experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%56%63%83%85%65%87%91%79%70%68%62%
Data source: Mount Isa September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Mount Isa in September

In Mount Isa, Australia, September marks the transition from the shorter days of winter to the longer days of spring, with an average daylight duration of 11 hours. This amount of sunlight mirrors the pattern seen in August, as daylight begins to stabilize after the gradual decline from the peak summer hours in January. As the month progresses, residents can enjoy more time outdoors, reflecting the district's vibrant transition into the warmer months ahead. Following September, daylight will start to increase again, setting the stage for the longer days of October and November, where sunlight reaches 12 and 13 hours, respectively. This cyclical trend not only enriches the landscape but also enhances the outdoor experiences that Mount Isa has to offer.

Average Daylight Hours in Mount Isa for September

The chart illustrates the variation in daylight duration in Mount Isa throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 13m12h 45m12h 11m11h 35m11h 6m10h 52m10h 59m11h 24m11h 58m12h 33m13h 5m13h 21m
Data source: Mount Isa daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Mount Isa

As September arrives in Mount Isa, Australia, the wind begins to pick up, with an average speed of 5.4 m/s (12 mph) marking a notable increase compared to the previous months. This brisk breeze reflects a trend of gradually intensifying winds leading into spring, following the calmer months of winter. Notably, after a steady rise from April and May, where winds were at 5.3 m/s, September stands out as the month that ushers in the strongest gusts of the year so far, gently reminding residents of the region's dynamic seasonal shifts. With October on the horizon showing a predicted decrease, September serves as a turning point, celebrating the vitality of nature before the winds begin to mellow again.

Average September Wind Speed in Mount Isa

The chart displays monthly wind speed patterns in Mount Isa, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.44.14.75.35.34.64.65.05.4 m/s3.94.54.0
Data source: Mount Isa September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Mount Isa Compares to Other Months

The weather in Mount Isa 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 Mount Isa and find detailed weather information for every month.

September and January present quite a contrast in weather. In September, temperatures range from a comfortable minimum of 9°C (48°F) to a maximum of 39°C (102°F), with an average of 24°C (75°F). The month is relatively dry, experiencing only about 5 mm (0.2 in) of precipitation over a single day, and maintaining a low humidity level of 32%.

In contrast, January sees much warmer temperatures, with a minimum of 22°C (72°F) and a maximum soaring to 43°C (110°F), averaging around 31°C (88°F). The month is significantly wetter, receiving approximately 55 mm (2.1 in) of rain over six days, and the humidity rises to a more uncomfortable 56%. For more detailed information, check out Mount Isa weather in January.

September and February present strikingly different weather conditions. In September, temperatures range from a mild 9°C (48°F) at night to a warm maximum of 39°C (102°F) during the day, with low humidity at 32% and minimal precipitation of just 5 mm (0.2 in) over one day. In contrast, February is significantly warmer, with nighttime lows of 18°C (65°F) and daytime highs reaching 42°C (107°F). This month sees more precipitation, accumulating 85 mm (3.4 in) over six days, and a higher humidity level of 62%. For a deeper dive into February weather specifics, you can explore this link: Mount Isa weather in February.

In September, Mount Isa experiences a more moderate climate with temperatures ranging from a cool 9°C (48°F) at night to a warm 39°C (102°F) during the day. The month is characterized by low humidity at 32% and minimal precipitation, averaging only 5 mm over just one day. In contrast, March brings much warmer temperatures, with a minimum of 18°C (66°F) and a maximum of 41°C (106°F). This month is significantly wetter, receiving an average of 87 mm of rainfall spread across six days and a much higher relative humidity of 71%. For a more detailed look at the weather in March, visit Mount Isa weather in March.

In September, the weather in Mount Isa features a warm average temperature of 24°C (75°F), with maximum highs reaching up to 39°C (102°F). The month experiences minimal precipitation, only about 5 mm (0.2 in) over a single day, and low humidity levels at 32%. In contrast, April sees slightly warmer average temperatures at 26°C (79°F) and a higher minimum of 11°C (51°F). Notably, April enjoys significantly lower precipitation, averaging just 1 mm (0.0 in) with no rain days, but the humidity is higher at 53%. For more detailed information, check Mount Isa weather in April.

In comparing the weather of September and May, September features a broader temperature range, with minimums around 9°C (48°F) and maximums reaching as high as 39°C (102°F), resulting in an average temperature of 24°C (75°F). In contrast, May sees slightly cooler temperatures, with minimums at 6°C (43°F) and maximums peaking at 32°C (91°F), leading to an average of 21°C (70°F). Precipitation is quite limited in both months, with September receiving only 5 mm (0.2 in) over a single day, while May is predominantly dry, logging just 1 mm (0.0 in) with no rainy days. Additionally, September experiences lower humidity at 32%, compared to May's higher 47%. For a more detailed look at May's weather, you can visit Mount Isa weather in May.

In comparing the weather of September to June, September boasts a significantly higher average temperature of 24°C (75°F) compared to June's 18°C (64°F). While both months experience low precipitation, September has slightly less at 5 mm (0.2 in) over 1 day, whereas June records 6 mm (0.2 in) with no rainy days. Humidity levels also differ, with June being more humid at 47% compared to September's drier 32%. For those interested in exploring more about the weather in June, you can check out Mount Isa weather in June.

When comparing the weather in September to July, it's clear that September is notably warmer, with average temperatures rising to 24°C (75°F) compared to July's average of 18°C (65°F). September also experiences higher maximum temperatures, reaching up to 39°C (102°F), while July peaks at a cooler 33°C (91°F). Moreover, September has considerably lower humidity at 32%, in contrast to July's 42%, contributing to a drier feel despite slightly more rain in September. July sees minimal precipitation, with only 1 mm (0.1 in) over no days, whereas September receives a bit more, with 5 mm (0.2 in) over just one day. For more detailed insights, you can check out the Mount Isa weather in July.

September weather shows a notable warmth compared to August, with average temperatures rising to 24°C (75°F) from August's 20°C (68°F). The maximum temperature in September can reach a scorching 39°C (102°F), significantly higher than August's peak of 34°C (94°F). While September experiences a slight increase in precipitation to 5 mm (0.2 in) over just one day, August remained completely dry with no recorded rainfall. Additionally, September's humidity at 32% is lower than August's 43%, contributing to a drier feeling in the air during the transition from summer to the beginning of autumn. For a closer look at August’s weather specifics, you can explore Mount Isa weather in August.

In September, the weather features a comfortable average temperature of 24°C (75°F), with a minimum of 9°C (48°F) and a maximum of 39°C (102°F). Precipitation is minimal, with only about 5 mm (0.2 in) falling over just one day, and the humidity sits at 32%. In contrast, October sees a slight increase in average temperatures to 28°C (83°F), with morning lows of 15°C (58°F) and maximums reaching 41°C (105°F). Rainfall also rises, with around 10 mm (0.4 in) over two days, but humidity decreases to 23%. For a detailed look at the specifics of October weather, visit Mount Isa weather in October.

In September, the weather is characterized by a minimum temperature of 9°C (48°F) and an average high of 24°C (75°F), with maximum temperatures reaching as high as 39°C (102°F). This month experiences very little precipitation with only 5 mm (0.2 in) over just one rainy day, and the humidity sits at 32%. In contrast, November sees slightly milder minimum temperatures averaging 13°C (57°F) and a warmer average high of 29°C (85°F), with extreme highs peaking at 41°C (107°F). The month is also wetter, accumulating 18 mm (0.7 in) of rainfall across four days, while humidity decreases slightly to 28%. For a closer look at what to expect during this month, you can visit Mount Isa weather in November.

In September, temperatures in Mount Isa range from a mild minimum of 9°C (48°F) to an average of 24°C (75°F), peaking at a sizzling 39°C (102°F). The month enjoys low humidity at 32% and minimal rainfall, only about 5 mm (0.2 in) over the course of just one day. In contrast, December brings higher temperatures, with a minimum of 17°C (63°F) and an average of 32°C (90°F), while reaching up to a sweltering 44°C (111°F). Humidity increases to 47%, and precipitation also rises to 20 mm (0.8 in) over three days, making for a more humid and wet month overall. For a more detailed look at the weather during this time, check out Mount Isa weather in December.

Compare Mount Isa's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Mount Isa

As September unfolds in Mount Isa, a notable shift in weather patterns emerges, embracing the arrival of spring. The temperatures soar, with maximum readings reaching 39°C, setting a striking contrast against the cooler winter months. With an average temperature of 24°C, the days are comfortably warm, while the nights can dip to around 9°C, offering a refreshing respite. Unlike the wetter months preceding it, September sees minimal precipitation, with just 5 mm recorded over a single day, enabling outdoor activities without the interruption of frequent rain. Humidity remains low at 32%, making the air feel pleasantly dry. For those keen on understanding the full scope of Mount Isa's climate, detailed insights can be found at Mount Isa Climate.