September Weather in La Rioja, Argentina

Last updated: August 21, 2025

September in La Rioja, Argentina offers a dynamic climate experience, where temperatures can soar to a maximum of 38°C (100°F) while averaging a comfortable 18°C (65°F). With minimum temperatures dipping to 2°C (35°F), the month showcases a remarkable contrast between warm days and cool nights. Rainfall is modest, with just 20 mm (0.8 in) expected across 3 days, contributing to a moderate humidity level of 51%. This transitional period marks the onset of spring, making it an exciting time to explore the region's breathtaking landscapes and vibrant flora.

September Temperature in La Rioja

As September rolls into La Rioja, Argentina, a gentle transition from winter to spring unfolds in the region's temperatures. With a minimum of 2°C (35°F) and an average rising to 18°C (65°F), the days start to warm, hinting at the summer heat to come. However, the maximum temperature still hits a robust 38°C (100°F), showcasing the region's characteristic climate variability. This month serves as a bridge, illustrating a steady upward trend in warmth as the cooler months recede, paving the way for the vibrant and sun-soaked days of October and beyond. The moderate temperatures make September an inviting time for visitors and locals alike to enjoy the thriving landscapes of La Rioja.

September Weather in La Rioja: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in La Rioja, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In La Rioja, 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).
JanFebMarAprMayJunJulAugSepOctNovDec817874695952515765727780
Data source: Temperature data for La Rioja 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 La Rioja

September in La Rioja, Argentina, marks a subtle transition in the region’s climate, bringing a modest precipitation total of 20 mm (0.8 in) over just three days of rain. While this amount is a noticeable increase from the dry spell of August, it still falls short compared to the more abundant rains of the earlier months. The trend showcases a gradual reduction in precipitation as summer peaks, with January to March receiving over 70 mm each month, which diminishes to a mere 2 mm (0.1 in) in August. As September rolls in, residents can expect a slight reprieve from the parched conditions, hinting at the upcoming changes in the weather pattern as the cooler months approach.

September Precipitation Trends in La Rioja

The chart displays monthly precipitation patterns in La Rioja, 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 La Rioja, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec7172733323115220344677
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in La Rioja

In September, La Rioja experiences a slight uptick in humidity, with levels reaching 51%. This marks a continuation of the gradual decline that begins in early summer, where humidity peaked at 66% in February and waned to 42% by August. As the region transitions from the arid chill of winter to the warmer spring months, humidity begins to stabilize. This moderate level, while lower than the previous months, reflects a temperate climate that gently prepares for the more humid conditions of the upcoming spring. The progressive shift towards increased moisture in the air hints at the refreshing changes that October will bring, continuing the dynamic weather patterns characteristic of La Rioja.

September Average Humidity in La Rioja

This chart illustrates the average monthly humidity levels in La Rioja, 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 La Rioja is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec63%66%68%83%82%72%57%42%51%47%58%62%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in La Rioja

In September, La Rioja, Argentina, experiences a UV Index of 9, categorizing it as very high with a burn time of just 15 minutes. This marks a notable transition as the region shifts from the extreme sun exposure of the winter months, reflected in the consistently high indexes of 15 and 14 in January and February, to a slightly lower but still significant level. As spring approaches, the UV Index begins to rise again in October, reaching 12, reminding residents and visitors alike to remain vigilant against sun damage. Emphasizing this trend, September serves as a crucial reminder of the need for sun protection as the intensity increases. For detailed information on UV levels throughout the year, check out La Rioja UV Index.

Maximum UV Index Levels in La Rioja for September

The chart shows the monthly maximum UV Index (UVI) for La Rioja 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 La Rioja typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec151412965579121415
Data source: La Rioja 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 La Rioja

September in La Rioja, Argentina, heralds the transition into spring with a delightful embrace of sunshine, offering an impressive 323 hours of sunlight. This marks a gentle ascent from the slightly warmer summer months, where sunlight peaks in January at 292 hours. As the region shifts from winter's grip, a noticeable increase in sunlight hours is observed, leading up to October’s brilliant 344 hours. Notably, this uptick continues throughout the spring, culminating in 372 hours by December, suggesting the region’s charm thrives under a generous sun. The rhythmic pattern of sunlight in La Rioja not only enhances the landscape but also invites locals and visitors alike to savor the vibrant outdoors, making September a season of invigorating warmth and beauty.

Monthly Sunshine Duration in La Rioja: September Highlighted

The September sunshine duration represents the total number of hours La Rioja 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.
JanFebMarAprMayJunJulAugSepOctNovDec292h305h320h282h277h276h301h319h323h344h359h372h
Data source: La Rioja September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in La Rioja During September

In September, La Rioja, Argentina, enjoys a favorable 86% chance of sunny weather, continuing the trend of high sunshine that peaks in the mid-year months. After a remarkable 93% in August, the sunny disposition slightly eases but remains strong, setting the tone for the vibrant spring season. This consistency in sunny days underscores a gradual increase in sunshine from the winter months through to spring, making September an ideal time for outdoor activities and exploration. With October showing a slight dip to 79%, September's brilliance serves as a perfect prelude to the warmer months ahead.

Percentage of Sunny Days in September in La Rioja

The chart illustrates the percentage of sunny days in La Rioja 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 La Rioja experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec61%60%56%67%69%70%83%93%86%79%74%59%
Data source: La Rioja September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in La Rioja in September

In September, La Rioja, Argentina experiences a continuation of the gradual shift towards longer days, offering about 11 hours of daylight. This marks a steady increase from the shorter days of winter, as the region transitions into spring. Following August, which also had 11 hours of daylight, September holds onto this balance before the days grow longer in October. Throughout the year, daylight duration fluctuates, peaking at 13 hours in the summer months of January and February, while the winter months see a reduction to 10 hours. This cyclical rhythm not only enhances the natural beauty of La Rioja but also invites locals and visitors to embrace the vibrant springtime as they relish the balance between daylight and night.

Average Daylight Hours in La Rioja for September

The chart illustrates the variation in daylight duration in La Rioja throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec13h 46m13h 4m12h 12m11h 20m10h 37m10h 16m10h 27m11h 5m11h 55m12h 48m13h 35m13h 58m
Data source: La Rioja daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in La Rioja

As September unfolds in La Rioja, Argentina, a gentle rise in the wind speed marks a subtle transition into the spring season. With an average wind speed of 2.7 m/s (6 mph), September experiences a notable increase, surpassing the more tranquil summer months that gradually settled into a consistent 2.1 to 2.5 m/s (5 mph) range. This refreshing gust heralds the promise of change, as the winds pick up slightly again in October and November, maintaining the invigorating pace of 2.6 and 2.7 m/s (6 mph) respectively. The invigorating breezes of September seem to capture the essence of blossoming spring, creating a vibrant atmosphere that encourages exploration and appreciation of the breathtaking landscapes of La Rioja.

Average September Wind Speed in La Rioja

The chart displays monthly wind speed patterns in La Rioja, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.02.32.12.22.12.22.22.7 m/s2.62.72.4
Data source: La Rioja September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in La Rioja Compares to Other Months

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

September and January present contrasting weather conditions. September sees a broader temperature range, with lows around 2°C (35°F) and highs reaching up to 38°C (100°F), resulting in an average temperature of 18°C (65°F). It experiences relatively low humidity at 51% and minimal precipitation, with just 20 mm (0.8 in) over approximately 3 days. In contrast, January is warmer overall, featuring a milder minimum temperature of 15°C (58°F) and maximums soaring to 41°C (107°F), with an average of 27°C (82°F). This month also brings more rain, totaling 71 mm (2.8 in) over 8 days, and higher humidity at 63%. For a deeper look at January's climate specifics, you can visit La Rioja weather in January.

In September, La Rioja experiences a marked temperature range, with minimums dipping to 2°C (35°F) and daytime averages around 18°C (65°F), peaking at a hot 38°C (100°F). The month sees relatively low precipitation at 20 mm (0.8 in) over just 3 days and humidity levels at a moderate 51%. In contrast, February brings warmer temperatures with minimums starting at 14°C (57°F) and averaging 25°C (78°F), hitting even higher highs of 40°C (104°F). This month also experiences significantly more rainfall, totaling 72 mm (2.9 in) over 8 days, accompanied by higher humidity at 66%. For more details on February weather in La Rioja, you can visit La Rioja weather in February.

In September, temperatures in La Rioja range from a cool 2°C (35°F) at night to a warm 38°C (100°F) during the day, with an average of 18°C (65°F). The month sees relatively low precipitation of 20 mm (0.8 in) over just three days, and humidity averages around 51%. In contrast, March experiences milder nighttime temperatures with a minimum of 10°C (51°F) and an average temperature of 23°C (74°F), while still reaching highs of 38°C (100°F). Rainfall increases significantly to 73 mm (2.9 in) over eight days, resulting in higher humidity levels averaging 68%. For more detailed weather information, visit La Rioja weather in March.

September and April present contrasting weather patterns. September typically experiences a wider temperature range, with minimums as low as 2°C (35°F) and highs reaching up to 38°C (100°F), while averaging around 18°C (65°F). In this month, precipitation is minimal at 20 mm (0.8 in) over about 3 days, and humidity levels hover around 51%. In contrast, April offers milder temperatures that range from a minimum of 7°C (45°F) to a maximum of 34°C (93°F), averaging 20°C (69°F). The month receives more precipitation, totaling 33 mm (1.3 in) across 6 days, and humidity is significantly higher at 83%. For a closer look at the weather specifics, you can explore La Rioja weather in April.

In comparing the weather between September and May, we observe notable differences in temperature and humidity. September features a wider temperature range, with minimums around 2°C (35°F) and maximums reaching as high as 38°C (100°F) on average. In contrast, May has a cooler average temperature, peaking at 28°C (83°F) and a similar minimum of 2°C (36°F). While September experiences less precipitation overall, with only about 20 mm (0.8 in) over three days, May sees slightly higher precipitation at 23 mm (0.9 in) spread over five days. Humidity levels also differ significantly, with September hovering around 51% compared to a much more humid 82% in May. For more detailed insights on May's weather, you can visit La Rioja weather in May.

In comparing the weather between September and June, September experiences a broader temperature range with minimums as low as 2°C (35°F) and maximums reaching up to 38°C (100°F), resulting in a much warmer average of 18°C (65°F). In contrast, June tends to be cooler, with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 24°C (76°F) and an average of 11°C (52°F). Precipitation is slightly higher in September, totaling 20 mm (0.8 in) over three days, compared to June's 11 mm (0.4 in) of rainfall over two days. Additionally, humidity levels are higher in June at 72%, compared to September's 51%. For a closer look at June’s weather specifics, visit La Rioja weather in June.

In comparing the weather between September and July, September emerges as a significantly warmer month. With minimum temperatures of 2°C (35°F) and an average high of 38°C (100°F), September experiences a broader temperature range compared to July, which has a minimum of -2°C (29°F) and a maximum of 25°C (78°F). Additionally, September has more precipitation, measuring at 20 mm (0.8 in) over three days, while July sees only 5 mm (0.2 in) of rain over one day. Furthermore, September's humidity is slightly lower at 51%, compared to July's 57%. For more details on July weather, you can visit La Rioja weather in July.

The weather in September shows significantly warmer conditions compared to August, with average temperatures rising from 14°C (58°F) to 18°C (65°F). While August temperatures range from a minimum of 0°C (33°F) to a maximum of 35°C (95°F), September presents a wider range, featuring lows of 2°C (35°F) and highs peaking at 38°C (100°F). Additionally, September experiences slightly more precipitation, accumulating 20 mm (0.8 in) over three days, while August remains notably dry with only 2 mm (0.1 in) across the entire month and no rainfall days at all. Humidity levels also increase from 42% in August to 51% in September, contributing to the overall warmer feel. For a detailed overview, visit La Rioja weather in August.

In September, the weather in La Rioja exhibits a notable range with minimum temperatures dropping to around 2°C (35°F) and maximums soaring to 38°C (100°F), resulting in an average of 18°C (65°F). Precipitation is relatively low at 20 mm (0.8 in) over just 3 days, accompanied by a humidity level of 51%.

In contrast, October brings a shift in climate, with minimum temperatures rising to 7°C (45°F) and an increase in the average temperature to 22°C (72°F). Maximums can reach up to 40°C (104°F), indicating a continuation of warmth as the month progresses. Precipitation also sees a notable increase, totaling 34 mm (1.3 in) over 5 days, while humidity decreases slightly to 47%.

For more details about October weather, you can visit La Rioja weather in October.

September and November offer distinct weather contrasts. In September, temperatures range from a chilly 2°C (35°F) to a warm 38°C (100°F), with an average of 18°C (65°F) and relatively low precipitation of 20 mm (0.8 in) over just 3 days. The humidity sits at a comfortable 51%. In comparison, November experiences milder lows at 11°C (52°F) and higher highs reaching up to 41°C (106°F), with a warmer average of 25°C (77°F). Rainfall increases to 46 mm (1.8 in) across 6 days, and humidity rises slightly to 58%. For more details about specific weather conditions, you can check La Rioja weather in November.

In September, the weather features a minimum temperature of 2°C (35°F), with an average of 18°C (65°F) and a maximum reaching 38°C (100°F). This month experiences relatively low precipitation at 20 mm (0.8 in) over just 3 days, combined with a humidity level of 51%. In contrast, December sees a warmer climate with minimum temperatures around 12°C (54°F), averaging 27°C (80°F), and highs peaking at 42°C (108°F). The precipitation increases significantly to 77 mm (3.0 in) spread over 7 days, alongside a higher humidity level of 61%. This shift underscores a dramatic change in weather patterns as the year progresses. For more details, you can check La Rioja weather in December.

Compare La Rioja's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in La Rioja

As September ushers in the transition from winter to spring in La Rioja, visitors can expect a delightful weather shift marked by a significant rise in temperatures, showcasing warm days contrasted with cooler nights. With average highs around 18°C and an occasional peak at 38°C, this month tends to be pleasantly mild, diverging from the colder winter months. The relatively low precipitation of just a few days also enhances outdoor activities, allowing for plenty of sunshine amidst the blooming landscapes. With humidity levels hovering around 51%, September offers a refreshing ambiance, making it an ideal time to explore the region's beauty. For more detailed insights, check out La Rioja Climate.