September Weather in La Union, Peru

Last updated: August 27, 2025

September in La Union, Peru presents a unique blend of cool temperatures and considerable precipitation, setting the stage for a varied climate experience. With maximum temperatures reaching 16°C (61°F) and averaging around 6°C (44°F), visitors can expect brisk days and chilly nights, occasionally dipping to -3°C (26°F). This month is marked by 21 days of rain, accumulating to 74 mm (2.9 in), contributing to the region's lush landscapes. The humidity level rests at a moderate 37%, ensuring that while the air may feel damp, it's manageable for outdoor exploration. Overall, September offers an intriguing insight into La Union’s transitional weather, perfect for those looking to experience its natural beauty amidst cooler, rainy days.

September Temperature in La Union

In September, La Union experiences a subtle transition as temperatures hover around the 6°C (44°F) mark on average. This month sees a slight chill with minimum temperatures averaging -3°C (26°F), resembling the brisk conditions of August and July. Although maximum temperatures reach 16°C (61°F), the overall trend reflects a gradual warming as the region approaches spring. This consistency in cooler nights and mild days echoes the preceding months, providing a crisp, invigorating atmosphere perfect for outdoor exploration and appreciation of the stunning Andean landscapes. As the weather gradually warms through October, visitors can expect a refreshing close to winter before the more temperate months ahead.

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

The chart illustrates September temperature patterns in La Union, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In La Union, 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).
JanFebMarAprMayJunJulAugSepOctNovDec454646454544434343454646
Data source: Temperature data for La Union 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 La Union

In September, La Union, Peru, experiences a notable uptick in precipitation, recording 74 mm (2.9 in) over 21 days. This increase marks a transitional phase as the dry season comes to an end, paving the way for the rainier months ahead. Compared to the drier months of July and August, where rainfall was a mere 29 mm (1.2 in) and 32 mm (1.3 in) respectively, September serves as a reminder of the region's climatic variability. As the year progresses, rainfall will continue to rise, peaking in March with an impressive 189 mm (7.5 in), indicating that the wet season is just around the corner. The gradual increase in precipitation not only revitalizes the landscape but also sets the stage for the flourishing biodiversity that defines this vibrant region.

September Precipitation Trends in La Union

The chart displays monthly precipitation patterns in La Union, 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 Union, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec1681781891106833293374121137166
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in La Union

In September, La Union experiences a notable shift in humidity, dropping to 37%, a stark contrast to the lush January levels of 88%. This trend of decreasing humidity is characteristic of the region during the winter months, as the dry season progresses through July and August. However, September’s humidity begins to hint at the upcoming transition, marking a gradual increase that continues into the wetter months. As the dry spell recedes, the significance of this modest rise becomes apparent and sets the stage for November's higher humidity of 73%, illustrating the intricate dance between the changing seasons in this coastal paradise.

September Average Humidity in La Union

This chart illustrates the average monthly humidity levels in La Union, 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 Union is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%86%89%89%86%71%44%34%37%50%73%91%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in La Union

In September, La Union, Peru experiences a high UV Index of 17, indicating an extreme exposure category, with a burn time of just 10 minutes. This trend continues from the preceding months of May through August, where the UV Index remains consistently high, especially in the peak summer months of January through April, which hold the highest index of 19. As October approaches, the UV Index slightly increases to 18, while November maintains a similar level. This data highlights the importance of sun protection during these months to avoid harmful UV exposure. For a more detailed understanding of the UV Index in La Union, visit La Union UV Index.

Maximum UV Index Levels in La Union for September

The chart shows the monthly maximum UV Index (UVI) for La Union 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 Union typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec191919191513141517181817
Data source: La Union 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 Union

September in La Union, Peru, baskes in an impressive 318 hours of sunshine, showcasing the region's beautiful transition into spring. The sun-kissed days follow a peak in sunlight during the previous months, with August leading at 332 hours. The gradual decline from the summer's heights marks the start of a serene phase that still welcomes plenty of bright, enjoyable days. As daylight hours decrease heading into October, which boasts 303 hours, September stands out as a vibrant reminder of the warmth and radiance of the preceding months. This consistent abundance of sunshine not only highlights La Union’s favorable climate but also offers an enchanting backdrop for outdoor adventures and exploration, making it a perfect time to soak up the last rays of the season before the year winds down.

Monthly Sunshine Duration in La Union: September Highlighted

The September sunshine duration represents the total number of hours La Union 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.
JanFebMarAprMayJunJulAugSepOctNovDec197h224h246h287h326h314h331h332h318h303h255h263h
Data source: La Union September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in La Union During September

In La Union, Peru, the chances of enjoying sunny weather see a noticeable shift as the year progresses. Starting from a low of 6% in January, the likelihood gradually increases, peaking in July with a robust 37% chance of sunshine. As the months transition into late summer, sunshine chances notably dip again, with September presenting a 21% likelihood, which is slightly lower than the height of summer but still offers a fair chance for warm, sunny days. This trend highlights the region's seasonal variability, making September a promising month for those hoping to soak in some sunshine amid cooler, cloudier months ahead.

Percentage of Sunny Days in September in La Union

The chart illustrates the percentage of sunny days in La Union 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 Union experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec6%8%5%12%24%22%37%30%21%13%5%12%
Data source: La Union September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in La Union in September

In September, La Union, Peru, experiences a refreshing return to 12 hours of daylight, marking a transition from the slightly shorter days of the previous months. This seasonal shift showcases a striking consistency in daylight hours throughout the year, with 12 hours dominating the summer months of January through March, and a brief dip to 11 hours during the cooler winter months from April to August. As September unfolds, the days lengthen again, smoothly transitioning into the equal daylight of October through December, creating a harmonious rhythm of light that defines La Union's unique climatic pattern.

Average Daylight Hours in La Union for September

The chart illustrates the variation in daylight duration in La Union throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec12h 36m12h 23m12h 7m11h 51m11h 39m11h 33m11h 36m11h 47m12h 2m12h 18m12h 32m12h 40m
Data source: La Union daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in La Union

As the calendar turns to September in La Union, Peru, the winds begin to whisper a gentle change. With an average wind speed of 1.5 m/s (3 mph), September showcases a slight dip from the summer peak but still maintains a refreshingly breezy atmosphere. This transitional month follows a summer season characterized by a gradual increase in wind speed, peaking at 1.6 m/s (4 mph) in July and August. As autumn approaches, dips in wind speed can be observed heading into October and November, suggesting a calming breath before the seasonal shift settles in. This subtle ebb and flow of the winds paints a picture of La Union's dynamic climate, inviting both residents and visitors to embrace the serene yet invigorating breezes of September.

Average September Wind Speed in La Union

The chart displays monthly wind speed patterns in La Union, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.31.31.31.31.41.41.61.61.5 m/s1.41.21.3
Data source: La Union September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in La Union Compares to Other Months

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

In comparing the weather between September and January, we see some notable differences. Both months experience a similar minimum temperature of around -3°C (26°F), but January tends to be slightly warmer overall, with an average temperature of 7°C (46°F) compared to September's 6°C (44°F). While September has a maximum temperature of 16°C (61°F), January reaches up to 17°C (62°F). Precipitation levels are significantly higher in January, with 168 mm (6.6 in) falling over 25 days, contrasting with September's 74 mm (2.9 in) spread over 21 days. Additionally, humidity is much greater in January at 88%, compared to 37% in September, making January feel much wetter and more humid. For a detailed look at January weather in this region, you can visit La Union weather in January.

In September, temperatures range from a chilly -3°C (26°F) to a mild 16°C (61°F), with an average of 6°C (44°F). The month experiences moderate precipitation at 74 mm (2.9 in) over 21 days, coupled with relatively low humidity at 37%. In contrast, February brings slightly warmer temperatures, with a minimum of -1°C (31°F) and a maximum of 17°C (62°F), averaging around 8°C (46°F). However, this month is significantly wetter, with precipitation totaling 178 mm (7.0 in) across 27 days and much higher humidity at 86%. For a closer look at February weather specifics, check out La Union weather in February.

September and March exhibit notable differences in weather conditions. In September, temperatures range from a chilly -3°C (26°F) to a comfortable 16°C (61°F), with an average of 6°C (44°F). The month sees moderate precipitation of 74 mm (2.9 in) over approximately 21 days, resulting in a relatively dry humidity level of 37%. In contrast, March brings slightly milder temperatures, with a minimum of 0°C (32°F), an average of 8°C (46°F), and a maximum of 16°C (61°F). However, it experiences significantly higher precipitation at 189 mm (7.5 in) spread over 30 days, leading to much higher humidity at 89%. For more detailed information, visit La Union weather in March.

When comparing the weather in September and April, notable differences emerge. In September, temperatures range from a minimum of -3°C (26°F) to a maximum of 16°C (61°F), with an average temperature of 6°C (44°F). The month sees a total precipitation of 74 mm (2.9 in) over 21 days and a relatively low humidity of 37%. In contrast, April experiences slightly milder temperatures with a minimum of -2°C (28°F) and a maximum of 17°C (63°F), averaging at 7°C (45°F). However, it experiences higher precipitation, totaling 110 mm (4.3 in) across 26 days, coupled with much higher humidity at 89%. For more detailed information on April conditions, you can check out La Union weather in April.

In comparing the weather of September and May, both months exhibit similar maximum temperatures, reaching around 16°C (61°F). However, September tends to be slightly cooler on average, with a minimal temperature of -3°C (26°F) compared to May's -2°C (29°F). Precipitation levels are quite comparable, with September receiving 74 mm (2.9 in) over 21 days and May having 68 mm (2.7 in) over 20 days. A notable difference is the humidity, which is significantly higher in May at 86%, while September enjoys a much drier atmosphere with only 37% humidity. For a closer look at weather specifics during May, check out La Union weather in May.

In comparing the weather of September and June, one can observe that both months have similar average temperatures, with September showing a min of -3°C (26°F) and a max of 16°C (61°F), while June experiences a min of -5°C (24°F) with the same maximum. However, September is marked by higher precipitation—74 mm (2.9 in) over 21 days—compared to June's 33 mm (1.3 in) across only 10 days. Additionally, humidity levels in June are significantly higher at 71%, compared to a drier 37% in September. For more specific information, visit La Union weather in June.

When comparing the weather in September and July, both months exhibit similar average temperatures, hovering around 6°C (44°F). However, September experiences slightly warmer extremes, with a maximum of 16°C (61°F) compared to July's maximum of 16°C (62°F). Notably, September is characterized by significantly higher precipitation, with 74 mm (2.9 in) falling over 21 days, in contrast to July's more mild 29 mm (1.2 in) over just 9 days. Additionally, humidity levels are higher in July at 44%, compared to September's 37%. For more detailed insights on July weather, you can visit La Union weather in July.

In comparing the weather conditions of September and August, we observe that both months feature relatively mild average temperatures, with September experiencing a minimum temperature of -3°C (26°F) and a maximum of 16°C (61°F), while August has slightly cooler extremes ranging from -5°C (23°F) to a maximum of 17°C (62°F). Although the average temperatures are similar, September tends to be wetter, receiving 74 mm (2.9 in) of precipitation over 21 days compared to August's 32 mm (1.3 in) across just 10 days. Additionally, September has a higher humidity level of 37%, compared to August's 34%. Overall, September brings a slight increase in warmth and significant precipitation when compared to August. For more detailed information, you can check La Union weather in August.

In comparing the weather between September and October, October tends to be slightly warmer and wetter. September has an average temperature of 6°C (44°F), with a maximum of 16°C (61°F) and minimum of -3°C (26°F), while October shows a marginal increase to an average of 7°C (45°F), with a maximum of 17°C (63°F) and a minimum of -2°C (29°F). Additionally, October experiences significantly more precipitation at 121 mm (4.8 in) over 28 days compared to September's 74 mm (2.9 in) across 21 days, leading to a rise in humidity from 37% to 50%. For more detailed insights, you can check La Union weather in October.

September and November show notable differences in weather patterns. While both months share similar minimum temperatures, September tends to be slightly cooler on average, with an average temperature of 6°C (44°F) compared to November's 8°C (46°F). Precipitation also varies significantly; September experiences 74 mm (2.9 in) over 21 days, whereas November sees increased rainfall of 137 mm (5.4 in) across 28 days, contributing to a much higher humidity level of 73% in November compared to the 37% in September. For more detailed insights into November's climate, you can check La Union weather in November.

In September, temperatures in La Union typically range from a minimum of -3°C (26°F) to a maximum of 16°C (61°F), with an average temperature of about 6°C (44°F). The month sees approximately 74 mm (2.9 in) of precipitation spread over 21 days, resulting in a relatively low humidity level of 37%. In contrast, December experiences slightly milder temperatures, with a minimum of -2°C (28°F) and a maximum of 18°C (65°F), averaging 8°C (46°F). However, it also brings significantly more rainfall, totaling around 166 mm (6.5 in) over 29 days, leading to a much higher humidity of 91%. For more details, check out La Union weather in December.

Compare La Union's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in La Union

September in La Union ushers in a shift in weather patterns, showcasing a more temperate climate compared to the sweltering summer months. The average temperatures hover around a cool 6°C, with nighttime dips, making it a refreshing contrast to the heat experienced earlier in the year. While September witnesses increased rainfall, totaling 74 mm over 21 days, this moisture is essential for revitalizing the landscape after the dry spells. The humidity, at 37%, lends a crispness to the air that invigorates both locals and visitors alike. For those curious about the year-round weather nuances in this picturesque region, more information can be found at La Union Climate.