September Weather in Santa Rosa, Argentina

Last updated: August 21, 2025

September in Santa Rosa, Argentina, presents a vibrant shift in weather as the region transitions into spring. Daytime temperatures soar to a maximum of 39°C (102°F), while the average settles around a comfortable 20°C (68°F). Nights can be cooler, with temperatures dipping to a minimum of 7°C (44°F). Despite enjoying many sunny days, the city experiences 104 mm (4.1 in) of rainfall over 9 days, contributing to an overall humidity level of 55%. This mix of warmth and occasional showers makes September an interesting month for both locals and visitors, showcasing the region's diverse climate as it blooms into the warmer months ahead.

September Temperature in Santa Rosa

September in Santa Rosa, Argentina, marks the transition from the chill of winter to the warmth of spring, bringing a delightful range of temperatures. With minimums averaging around 7°C (44°F), the cooler mornings give way to pleasant averages of 20°C (68°F), while the maximums can soar up to 39°C (102°F), hinting at the approaching summer heat. This month stands out as a refreshing period where the weather is generally mild, making it an ideal time for outdoor activities. As the temperatures gradually trend upwards, September sets the stage for the beautiful, sun-soaked days that characterize the upcoming months in Santa Rosa, inviting both locals and visitors to enjoy the blossoming landscape.

September Weather in Santa Rosa: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santa Rosa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santa Rosa, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec828076716461596367727680
Data source: Temperature data for Santa Rosa 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 Santa Rosa

In September, Santa Rosa experiences a noteworthy shift in its precipitation patterns, receiving 104 mm (4.1 in) of rain over 9 days. This marks a significant increase from the drier months of July and August, which saw only 40 mm (1.6 in) and 47 mm (1.9 in) respectively. The return of rainfall is indicative of the transition into spring, bringing with it a refreshing revitalization to the landscape after a relatively arid winter. As the region continues to experience fluctuating precipitation levels, September stands out as a pivotal month that bridges the gap between the dryness of winter and the wetter spring months ahead, setting an exciting tone for the coming season.

September Precipitation Trends in Santa Rosa

The chart displays monthly precipitation patterns in Santa Rosa, 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. In Santa Rosa, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec16971144130129664047104106136113
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Santa Rosa

In September, Santa Rosa, Argentina, experiences a moderate humidity level of 55%, marking a slight increase from the drier month of August, which recorded just 46%. As winter transitions to spring, humidity levels begin to rise, yet they remain significantly lower than the peak seen in the colder months of May and April, where humidity soared to 84% and 81%, respectively. This gradual uptick hints at the arrival of warmer seasons, as the city moves toward the more humid months ahead, while still offering a comfortable atmosphere for outdoor activities. With October following closely with a humidity of 57%, the region is poised for an invigorating change in climate.

September Average Humidity in Santa Rosa

This chart illustrates the average monthly humidity levels in Santa Rosa, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Santa Rosa is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec66%61%71%81%84%76%64%46%55%57%59%75%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Santa Rosa

As September arrives in Santa Rosa, Argentina, the UV Index reaches a notable 10, categorized as very high, which means that sun protection is essential, with a burn time of just 15 minutes. This marks a transition from the milder summer sun, as the UV levels dip slightly from the extreme highs of the earlier months. Interestingly, the trends reveal a consistent pattern of increasing UV exposure from winter to spring, emphasizing the need for vigilance against sunburn even in early spring. Those planning outdoor activities should be well-prepared to safeguard their skin. For more details, check out the Santa Rosa UV Index for up-to-date information and tips.

Maximum UV Index Levels in Santa Rosa for September

The chart shows the monthly maximum UV Index (UVI) for Santa Rosa 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. In September, the maximum UV index in Santa Rosa typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec15131210655710121414
Data source: Santa Rosa 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 Santa Rosa

September in Santa Rosa, Argentina, marks a delightful transitional phase where the warmth of spring begins to envelop the region. With 278 hours of sunshine, the month maintains a comfortable glow, continuing the upward trend in daylight as the year progresses. After the cooler winter months, the sunshine gradually increases from 223 hours in June to 298 hours in October, creating a vibrant atmosphere that encourages outdoor activities and vibrant community events. This perfect balance of sunshine not only enhances the natural beauty of the landscape but also infuses a sense of renewal and optimism, making September a particularly inviting time to experience all that Santa Rosa has to offer.

Monthly Sunshine Duration in Santa Rosa: September Highlighted

The September sunshine duration represents the total number of hours Santa Rosa 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.
JanFebMarAprMayJunJulAugSepOctNovDec274h313h314h272h233h223h241h288h278h298h324h376h
Data source: Santa Rosa September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Santa Rosa During September

In September, the likelihood of sunny weather in Santa Rosa, Argentina hovers around 55%, indicating a somewhat balanced chance of clear skies. This positions September in the middle of the spectrum, following a peak in August with 71% sunny days. As the seasons transition, sunshine becomes more prevalent again in the subsequent month, October, which sees a rise to 64%. Overall, while September may not deliver the sunniest conditions of the year, it does suggest an optimistic blend of pleasant weather and the pleasant anticipation of more consistent sunshine ahead.

Percentage of Sunny Days in September in Santa Rosa

The chart illustrates the percentage of sunny days in Santa Rosa 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 Santa Rosa experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec52%67%52%64%63%45%62%71%55%64%66%74%
Data source: Santa Rosa September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Santa Rosa in September

In September, Santa Rosa, Argentina, enjoys about 11 hours of daylight, marking a gentle transition as the days begin to lengthen once again. Following the relatively consistent daylight duration of 10 hours during the winter months, September brings a slight increase that continues into October. This month serves as a bridge from the cooler days of autumn towards the warmth of spring, underscoring the city's moderate climate. The trend of increasing daylight duration becomes more pronounced as the year advances, culminating in the longer days of late spring and early summer, where residents can bask in up to 13 hours of sunlight. Such seasonal fluctuations not only highlight the region's temperate nature but also invite outdoor activities as the days grow brighter.

Average Daylight Hours in Santa Rosa for September

The chart illustrates the variation in daylight duration in Santa Rosa throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 41m13h 2m12h 12m11h 22m10h 41m10h 21m10h 32m11h 8m11h 55m12h 46m13h 30m13h 53m
Data source: Santa Rosa daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Santa Rosa

As September arrives in Santa Rosa, Argentina, it ushers in a noticeable shift in the winds, with average speeds climbing to 4.3 m/s (10 mph)—the highest recorded this year. Following a summer of gentler breezes, the transition into spring reveals a trend of increasing wind activity, pushing past the previous months, which lingered around 3.1 to 3.9 m/s. This invigorating uptick not only enhances the freshness of the air but also signals a dynamic change in the landscape, as the city embraces the bustling energy of the new season. The preceding months have gently prepared Santa Rosa for this invigorating burst of movement, and as the winds pick up, residents can expect the corners of outdoor cafés to flutter more vibrantly, mirroring the lively spirit of early spring.

Average September Wind Speed in Santa Rosa

The chart displays monthly wind speed patterns in Santa Rosa, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.73.13.13.33.53.63.63.94.3 m/s3.93.93.8
Data source: Santa Rosa September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Santa Rosa Compares to Other Months

Weather in Santa Rosa varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Santa Rosa, focusing on differences in temperature, rainfall, humidity, and UV levels.

In September, temperatures range from a minimum of 7°C (44°F) to a maximum of 39°C (102°F), with an average of 20°C (68°F). The month sees around 104 mm (4.1 in) of precipitation over approximately 9 days, accompanied by a humidity level of 55%. In contrast, January brings warmer weather, with temperatures varying from a minimum of 15°C (58°F) to a high of 43°C (109°F), and an average temperature of 28°C (82°F). January also experiences more rainfall, with 169 mm (6.6 in) over 10 days, and increased humidity at 66%. This shift illustrates a transition from the cooler, drier September to the hotter and more humid conditions of January. For more detailed information, you can check out Santa Rosa weather in January.

In comparing the weather between September and February, we notice some significant differences. September experiences a wider temperature range, with minimums dropping to 7°C (44°F) and maximums soaring to 39°C (102°F), while February tends to be milder overall, with minimums starting at 13°C (55°F) and maxing out at 42°C (107°F). Precipitation levels are higher in September, totaling 104 mm (4.1 in) over roughly 9 days, compared to February's 71 mm (2.8 in) over 8 days. Additionally, February has slightly higher humidity at 61%, compared to September's 55%. For a more detailed look at the February climate, check out Santa Rosa weather in February.

In September, the weather features a wide range of temperatures, with a minimum of 7°C (44°F) and an average of 20°C (68°F), while highs can reach up to 39°C (102°F). This month experiences about 104 mm (4.1 in) of precipitation over 9 days, alongside a moderate humidity of 55%. In contrast, March presents slightly warmer conditions, with a minimum temperature of 12°C (53°F), an average of 24°C (76°F), and maximums soaring to 40°C (104°F). The precipitation in March is higher at 144 mm (5.7 in), also spread over 9 days, but with increased humidity at 71%. For more detailed insights, visit Santa Rosa weather in March.

When comparing the weather in September and April, we notice some distinct differences. In September, temperatures range from a minimum of 7°C (44°F) to a maximum of 39°C (102°F), with an average temperature of 20°C (68°F). This month experiences 104 mm (4.1 in) of precipitation over about 9 days, with a moderate humidity level of 55%.

In contrast, April generally enjoys milder conditions, with slightly higher temperatures ranging from a minimum of 8°C (46°F) to a maximum of 35°C (95°F) and an average of 22°C (71°F). This month sees higher precipitation levels, averaging 130 mm (5.1 in), but over fewer days of rain (7 days), accompanied by a significantly higher humidity of 81%.

For more detailed insights, you can check out Santa Rosa weather in April.

When comparing the weather in September and May, notable differences emerge in temperature and humidity. September experiences a wider temperature range, with minimums of 7°C (44°F) and maximums reaching up to a scorching 39°C (102°F), while May sees cooler temperatures, with minimums at 5°C (41°F) and a maximum of 32°C (89°F). Despite September having a slightly lower average temperature of 20°C (68°F) compared to May's 18°C (64°F), it has lower humidity at 55%, in contrast to May's higher 84%. Precipitation is also slightly less in September, totaling 104 mm (4.1 in) over about 9 days, compared to May's 129 mm (5.1 in) over 10 days. For more detailed insights, check Santa Rosa weather in May.

When comparing the weather in September and June, notable differences arise. September experiences significantly higher temperatures, with an average of 20°C (68°F) and a maximum reaching 39°C (102°F), while June has a cooler average of 16°C (61°F) and peaks at 32°C (89°F). Precipitation is also more abundant in September, totaling 104 mm (4.1 in) across about 9 days, compared to June’s 66 mm (2.6 in) over nearly 8 days. Furthermore, June tends to be more humid, with a humidity level of 76% compared to September's 55%. For more detailed insights into June weather, you can visit Santa Rosa weather in June.

In comparing the weather of September and July, we see distinct differences in temperature and precipitation. September typically experiences a wider temperature range, with minimums of 7°C (44°F) and maximums soaring up to 39°C (102°F), contrasted with July's cooler averages, where temperatures range from 0°C (32°F) to a maximum of 32°C (91°F). Additionally, September records more precipitation with 104 mm (4.1 in) falling over nine days, compared to July's milder 40 mm (1.6 in) over five days. Interestingly, while humidity in July averages at 64%, it dips slightly to 55% in September. For a more detailed look at July's conditions, you can visit Santa Rosa weather in July.

In September, the weather experiences a noticeable transition compared to August. While August sees minimum temperatures drop to 0°C (32°F) and an average of 17°C (63°F), September boasts higher minimums at 7°C (44°F) and an average of 20°C (68°F). The maximum temperatures also rise slightly, from 37°C (99°F) in August to 39°C (102°F) in September. Additionally, September is wetter with 104 mm (4.1 in) of precipitation over 9 days, compared to August's 47 mm (1.9 in) over just 5 days. Humidity levels also increase from 46% in August to 55% in September, reflecting the shift in conditions. For a more detailed view of August weather patterns, you can check Santa Rosa weather in August.

September and October display a transition in weather patterns, with October generally feeling slightly warmer and more humid. In September, temperatures range from a minimum of 7°C (44°F) to a maximum of 39°C (102°F), averaging around 20°C (68°F). The month sees 104 mm (4.1 in) of precipitation over 9 days, accompanied by a humidity level of 55%. In contrast, October starts with a higher minimum temperature of 10°C (50°F) and an average of 22°C (72°F), peaking at 41°C (107°F). Precipitation increases slightly to 106 mm (4.2 in) over 10 days, with humidity rising to 57%. For more detailed insights, you can check Santa Rosa weather in October.

In September, temperatures begin cooler, with a minimum of 7°C (44°F) and an average of 20°C (68°F), while reaching a maximum of 39°C (102°F). The month sees approximately 104 mm (4.1 in) of precipitation over 9 days, accompanied by a humidity level of 55%. In contrast, November experiences warmer temperatures, with a minimum of 11°C (52°F), an average of 25°C (76°F), and a peak of 40°C (104°F). Although November receives slightly more rain, totaling 136 mm (5.4 in) over 8 days, the humidity increases to 59%. For more detailed information regarding the weather in November, you can check Santa Rosa weather in November.

September and December offer contrasting weather patterns. In September, temperatures range from a cooler minimum of 7°C (44°F) to a warm maximum of 39°C (102°F), averaging around 20°C (68°F). The month experiences moderate rainfall with a total of 104 mm (4.1 in) spread over 9 days and a humidity level of 55%. In contrast, December sees warmer temperatures, with a minimum of 13°C (55°F) and an average of 26°C (80°F), peaking at 40°C (104°F). Precipitation slightly increases to 113 mm (4.5 in) over just 7 days and the humidity rises to 75%. For more information, check Santa Rosa weather in December.

Compare Santa Rosa's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Santa Rosa

As September rolls into Santa Rosa, the weather showcases a delightful transition, marked by a blend of warm days and cooler nights. With maximum temperatures hitting a toasty 39°C, it is a stark shift from the more moderate summer months, while the average temperature settles comfortably at 20°C. However, as the month progresses, the minimum temperatures can dip to 7°C, adding a crisp touch to the evenings. September also brings a splash of rainfall with about 104 mm over 9 days, contributing to a humidity level of 55% that enhances the vibrant atmosphere of spring. This unique combination makes September a truly dynamic month in Santa Rosa, one worth experiencing. Discover more about its climate at Santa Rosa Climate.