September Weather in La Union, Mexico

Last updated: April 22, 2025

In September, La Union, Mexico, experiences warm to hot weather, with maximum temperatures reaching up to 38°C (101°F) and an average of 28°C (83°F). The minimum temperature typically hovers around 22°C (72°F), providing relatively mild nights. However, this month is also characterized by significant precipitation, with an average of 209 mm (8.2 in) spread over 23 days, leading to a rather humid atmosphere at 87%. Visitors should prepare for a mix of sunny and rainy days, making it essential to stay hydrated and plan activities accordingly.

September Temperature in La Union

September in La Union, Mexico, offers a warm embrace as summer winds down, with temperatures maintaining a comfortable range. Average temperatures hover around 28°C (83°F), providing a pleasant backdrop for outdoor activities. The month starts off with a minimum of 22°C (72°F), while daytime highs can reach up to 38°C (101°F). This consistent warmth reflects a trend seen throughout the summer months, ensuring that visitors can fully enjoy the vibrant culture and stunning landscapes this coastal area has to offer. As the days begin to cool slightly in October, September stands out as a lingering slice of summer bliss.

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.
JanFebMarAprMayJunJulAugSepOctNovDec737679838684858482807674
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, Mexico experiences a significant uptick in rainfall, with precipitation amounting to 209 mm (8.2 in) over 23 days. This marks a continuation of the heightened precipitation trend observed since June, where the region begins to transition into its wetter season. The month stands out not only for the volume of rain but also for the frequency of rainy days, as La Union, on average, sees more days of precipitation than any month preceding it. This saturation sets the stage for October's even more dramatic rainfall totals, positioning September as a pivotal month in the region's climatic patterns.

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.
JanFebMarAprMayJunJulAugSepOctNovDec100463649982596411621030516999
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in La Union

In September, La Union, Mexico, experiences a peak in humidity at 87%, maintaining the high levels established in August. This month marks a transition into the more humid fall months, with humidity steadily rising from the drier days of April, when it dropped to 59%. Such elevated humidity levels in September create a tropical atmosphere, often accompanied by heightened rainfall. As the year progresses into October and November, the humidity remains consistently high at 88%, emphasizing the region's tropical climate. This trend showcases a notable shift from the cooler, drier months of early spring to the lush, humid conditions typical of late summer and autumn.

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, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec83%76%66%59%64%69%82%87%87%88%88%88%
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 experiences a notably high UV Index of 13, placing it firmly in the extreme exposure category with a burn time of just 10 minutes. This marks a continuation of the intense sun conditions witnessed throughout the summer months, maintaining the trend seen from June to August. As we transition into October, the UV Index slightly decreases to 12 but remains extreme, highlighting the persistent need for sun protection. Travelers and locals alike should remain vigilant during this time to safeguard their skin. For more insights and specific precautions, check out 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.
JanFebMarAprMayJunJulAugSepOctNovDec911131413141313131298
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, Mexico, continues to bask in the glory of abundant sunshine, with an impressive 291 hours of sun this month. Following the peak summer months of July and August, which boasted 327 and 322 hours respectively, September marks a slight decline yet remains well above the earlier months, including January’s modest 204 hours. This transition hints at a gradual shift towards autumn but keeps the spirit of summer alive with remarkable daylight hours. As autumn approaches, the sunny days of September offer a perfect backdrop for outdoor activities, ensuring visitors and locals alike can savor lingering summer vibes before the year draws to a close.

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.
JanFebMarAprMayJunJulAugSepOctNovDec204h261h303h305h317h281h327h322h291h279h267h270h
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

As summer wanes into September, La Union, Mexico experiences a notable dip in sunny weather, with only a 26% chance of sunshine. This decline follows the peak months of March and April, where sunny days flourish at 71% and 58%, respectively. The trend reveals a consistent pattern of decreasing sunlight from the vibrant spring months into the late summer, with September trailing behind the preceding months of August and July, which see 34% and 35% chances of sunny weather. As autumn approaches, visitors should anticipate a more overcast ambiance, making early fall a time to embrace La Union's charm amidst the clouds.

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.
JanFebMarAprMayJunJulAugSepOctNovDec39%68%71%58%40%19%35%34%26%39%48%71%
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 La Union, Mexico, September marks a seamless transition in daylight duration, offering approximately 12 hours of sunlight each day. This month reflects a continued trend seen since the summer, where daylight peaks at 13 hours in June and July before gently tapering off. Following a slight decline in August, the consistent 12-hour rhythm of September has a warm reassurance that welcomes the onset of autumn. As the year progresses into October, daylight begins to diminish again, settling into the shorter days characteristic of winter. This cyclical pattern not only enhances the beauty of the region but also invites both locals and visitors to bask in the golden hues of early fall.

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.
JanFebMarAprMayJunJulAugSepOctNovDec11h 11m11h 33m12h 3m12h 32m12h 57m13h 9m13h 2m12h 40m12h 12m11h 42m11h 17m11h 4m
Data source: La Union daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in La Union

As summer draws to a close, September in La Union, Mexico is marked by a noticeable decline in wind speed, averaging just 1.5 m/s (3 mph). This gentle breeze contrasts sharply with the lively gusts of July, which peak at 2.7 m/s (6 mph), and hints at the mellow transition into fall. The trend suggests a gradual calming over the months, with winds steadily decreasing since the bustling summer months, offering a serene and tranquil atmosphere perfect for beach relaxation. By October and November, the conditions remain unchanged, maintaining that same soft touch of wind, creating an inviting environment for those seeking peace in this coastal paradise.

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.
JanFebMarAprMayJunJulAugSepOctNovDec2.32.22.32.12.01.62.72.31.5 m/s1.51.52.1
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

The weather in La Union 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 La Union and find detailed weather information for every month.

September and January present stark contrasts in weather conditions. In September, temperatures soar with a minimum of 22°C (72°F) and can peak at a scorching 38°C (101°F), averaging around 28°C (83°F). This month also sees significant rainfall, with 209 mm (8.2 in) over 23 days, contributing to a high humidity level of 87%. In contrast, January offers a much cooler climate, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 34°C (93°F), and an average of 23°C (74°F). Precipitation decreases to 100 mm (3.9 in) over just 9 days, and humidity is slightly lower at 83%. For more details, check out La Union weather in January.

September and February display contrasting weather patterns. September boasts higher temperatures, with a minimum of 22°C (72°F) and an average of 28°C (83°F), peaking at a scorching 38°C (101°F). In addition, it experiences significant rainfall, totaling 209 mm (8.2 in) over 23 days, coupled with high humidity at 87%. In stark comparison, February offers milder conditions, with a minimum of 13°C (56°F), an average of 25°C (76°F), and a maximum of 35°C (95°F). Rainfall is much less frequent in February, with only 46 mm (1.8 in) over 5 days and lower humidity at 76%. For more details about the weather during this month, visit La Union weather in February.

September and March offer contrasting weather experiences. In September, temperatures range from a minimum of 22°C (72°F) to a maximum of 38°C (101°F), with an average of 28°C (83°F). This month is also characterized by significant rainfall, averaging 209 mm (8.2 in) over 23 rainy days, and high humidity levels of 87%. In contrast, March is milder with temperatures ranging from 15°C (60°F) to 37°C (99°F) and an average of 26°C (79°F). Precipitation is minimal during this time, totaling only 36 mm (1.4 in) over just 6 days, accompanied by a lower humidity level of 66%. For more specifics about the weather during March, you can visit La Union weather in March.

September and April present contrasting weather patterns, particularly in terms of temperature and precipitation. In September, temperatures range from a minimum of 22°C (72°F) to a maximum of 38°C (101°F), with an average of 28°C (83°F). This month is characterized by high humidity at 87% and significant rainfall, totaling 209 mm (8.2 in) over 23 days. In contrast, April boasts warmer peak temperatures, reaching up to 41°C (106°F), with an average of 29°C (84°F) and a lower minimum of 17°C (63°F). However, April experiences far less precipitation, with only 49 mm (1.9 in) falling over just 7 days and a humidity level of 59%. For a more comprehensive look at April's weather, you can visit La Union weather in April.

September and May showcase distinct weather patterns. In September, temperatures range from a minimum of 22°C (72°F) to a maximum of 38°C (101°F), with an average temperature of 28°C (83°F). This month also sees significant precipitation, with 209 mm (8.2 in) over 23 days, contributing to high humidity levels at 87%. In contrast, May presents warmer conditions, featuring a minimum of 19°C (66°F) and a maximum of 41°C (106°F), while maintaining an average of 30°C (86°F). Precipitation in May is considerably lower at 98 mm (3.9 in), occurring over just 11 days, and humidity is less intense at 64%. For more detailed insights, you can visit La Union weather in May.

In comparing the weather of September and June, both months share similar temperature ranges, with minimum temperatures consistently at 22°C (72°F) and maximum temperatures peaking at 38°C (101°F). However, September has an average temperature of 28°C (83°F), slightly lower than June's average of 29°C (84°F). Precipitation levels differ notably; September experiences 209 mm (8.2 in) over 23 days, while June records a higher 259 mm (10.2 in) across 18 days, suggesting June is generally wetter despite having fewer rainy days. Additionally, humidity levels are higher in September at 87% compared to June's 69%, making September feel more humid overall. For further insights, you can check La Union weather in June.

When comparing the weather in September and July, both months exhibit warm temperatures, but there are some notable differences. September tends to be slightly cooler on average, with temperatures ranging from a minimum of 22°C (72°F) to a maximum of 38°C (101°F), alongside higher humidity levels at 87%. In contrast, July experiences higher maximum temperatures, reaching 40°C (104°F), with an average of 29°C (85°F), but enjoys relatively lower humidity at 82%. Furthermore, September is significantly wetter, with 209 mm (8.2 in) of precipitation over 23 days, compared to July's 64 mm (2.5 in) over just 13 days. For a more detailed look at July's weather, you can visit La Union weather in July.

In comparing the weather of September and August, both months experience similar high temperatures, with minimums of around 22°C (72°F) and maximums reaching up to 38°C (101°F). However, September tends to be slightly cooler on average, with an average temperature of 28°C (83°F) compared to August's 29°C (84°F). Notably, September is characterized by significantly higher precipitation, recording 209 mm (8.2 in) over 23 rainy days, whereas August sees only 116 mm (4.6 in) across 19 rainy days. Despite this difference in rainfall, humidity remains constant at 87% for both months. For more insights into the weather patterns of August, check out La Union weather in August.

September and October exhibit notable differences in weather patterns. September typically sees higher temperatures, with a minimum of 22°C (72°F) and an average of 28°C (83°F), peaking at 38°C (101°F). In contrast, October is slightly cooler, with a minimum temperature of 20°C (67°F) and an average of 27°C (80°F), while the maximum reaches 35°C (96°F). Precipitation also increases in October, totaling 305 mm (12.0 in) over 22 days, compared to September's 209 mm (8.2 in) across 23 days. Both months share similar humidity levels, hovering around 87-88%. For more specifics on October weather, check out La Union weather in October.

In September, the weather is notably warmer, with average temperatures reaching 28°C (83°F) and maximum highs soaring up to 38°C (101°F). There's also a significant amount of rain, with 209 mm (8.2 in) of precipitation over an average of 23 days, accompanied by a high humidity level of 87%. In contrast, November experiences cooler temperatures, with a minimum of 16°C (61°F) and a maximum of 34°C (94°F), leading to a more comfortable average of 25°C (77°F). Precipitation decreases to 169 mm (6.6 in) over 16 days, while humidity remains slightly higher at 88%. For more detailed information, you can check La Union weather in November.

In September, the weather is significantly warmer, with average temperatures reaching 28°C (83°F) and maximums soaring up to 38°C (101°F). This month also experiences high humidity at 87% and substantial rainfall, with 209 mm (8.2 in) falling over 23 days. In contrast, December brings cooler conditions, with average temperatures dropping to 23°C (74°F) and maximums peaking at 33°C (92°F). The precipitation decreases to 99 mm (3.9 in) over just 11 days, and humidity remains relatively stable at 88%. For more details on December's weather, you can check 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 brings a notable shift in weather, characterized by a combination of high humidity and frequent rainfall that sets it apart from other months. With an average temperature lingering around a comfortable 28°C, the warmth is underlined by occasional peaks reaching 38°C, making for humid days that require some patience. The 209 mm of rain spread over 23 days means that visitors and residents can expect a significant number of wet days, enhancing the lush environment but demanding preparedness for outdoor plans. For those interested in understanding the intricacies of La Union's weather patterns throughout the year, visit La Union Climate for more detailed insights.