September Weather in Los Angeles, United States

Last updated: February 24, 2025

In September, Los Angeles experiences warm and inviting weather, characterized by a maximum temperature reaching up to 45°C (113°F) and a comfortable average of 23°C (74°F). The minimum temperature rarely dips below 13°C (55°F), ensuring pleasant evenings. With a mere 3 mm (0.1 in) of precipitation and no rain days, visitors can enjoy the sunshine without interruption. The humidity level of 68% adds a mild tropical touch, making this month ideal for outdoor activities and exploration in the vibrant city.

September Temperature in Los Angeles

In September, Los Angeles experiences a delightful transition as summer begins to ebb. The temperatures swing between a cozy minimum of 13°C (55°F) and a stunning maximum of 45°C (113°F), accompanied by an average of 23°C (74°F), making it one of the warmest months of the year. Surprisingly, despite the lingering heat, there is a slight cool-down from the sweltering highs of July and August, suggesting an upcoming change in season. This month presents an inviting mix of sun-soaked days perfect for outdoor activities, while evenings cool just enough to enjoy a pleasant breeze, embodying the essence of Southern California’s climate.

September Weather in Los Angeles: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Los Angeles, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec565759646570757674706356
Data source: Temperature data for Los Angeles 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 Los Angeles

September in Los Angeles typically sees a noticeable drop in precipitation, mirroring the city's ongoing dry spell as summer transitions into fall. With only 3 mm (just 0.1 in) of rain measured, this month reflects a stark contrast to the wetter winter months that follow. Over the years, September has averaged no recorded precipitation days, highlighting its role as a dry period before the rainy season begins in October. This trend underscores the comforting predictability of Southern California's climate, where sun-drenched days are often the norm, and rain is a welcome, albeit rare, occurrence. As October approaches, the anticipation of slightly wetter weather begins to build, yet September remains a quintessential representation of Los Angeles's warm and dry reputation.

September Precipitation Trends in Los Angeles

The chart displays monthly precipitation patterns in Los Angeles, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7155701912322381876
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Los Angeles

As summer wanes, September in Los Angeles presents a slight dip in humidity, dropping to 68%, the lowest level recorded since May. This decline marks a gradual trend toward drier conditions that begins in August, which had a humidity of 69%. Throughout the year, Los Angeles experiences its highest humidity in the early months, peaking at 79% in February. However, as the year progresses, humidity levels consistently decrease, reaching their annual low by the time October rolls around at 67%. This decline not only enhances the city’s appealing autumn climate but also hints at a refreshing transition toward the cooler months ahead.

September Average Humidity in Los Angeles

This chart illustrates the average monthly humidity levels in Los Angeles, 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.
JanFebMarAprMayJunJulAugSepOctNovDec74%79%75%71%70%72%73%69%68%67%68%71%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Los Angeles

As September rolls into Los Angeles, the UV Index remains at a striking 10, indicative of a very high exposure risk that persists from the prior summer months. This trend of elevated UV levels, peaking with an extreme rating in the height of summer, underscores the importance of sun safety, with a burn time of just 15 minutes. The consistency in UV Index readings highlights a pattern where late summer sun intensity does not wane significantly, maintaining the need for protection. Those in the City of Angels must stay vigilant to safeguard their skin, reminding us that the sun’s rays can be deceptively strong even as autumn approaches. For more details, check out the comprehensive guide on Los Angeles UV Index.

Maximum UV Index Levels in Los Angeles for September

The chart shows the monthly maximum UV Index (UVI) for Los Angeles 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.
JanFebMarAprMayJunJulAugSepOctNovDec46891011111010754
Data source: Los Angeles 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 Los Angeles

September in Los Angeles shines with 314 hours of sunshine, marking a continuation of the summer's warmth as it transitions into fall. This month typically retains a significant amount of sunlight, reminiscent of the peak summer months, with June basking in 364 hours and July hitting a high of 380 hours. Although a slight dip from the heights of summer, September beautifully balances warmth and daylight, offering a perfect backdrop for outdoor activities. As the days shorten towards October, which features 292 hours of sunshine, the golden glow of early autumn continues to beckon locals and visitors alike, inviting them to relish in the lingering summer vibes before the cooler months set in.

Monthly Sunshine Duration in Los Angeles: September Highlighted

The September sunshine duration represents the total number of hours Los Angeles 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.
JanFebMarAprMayJunJulAugSepOctNovDec187h228h281h314h348h364h380h360h314h292h255h225h
Data source: Los Angeles September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Los Angeles During September

As September rolls around in Los Angeles, the likelihood of enjoying sunny weather reaches an impressive 74%, marking it as one of the sunniest months of the year. This increase follows a gradual uptick in sunny days from earlier months, such as August at 72% and June and July, both at 68%. With September's sunny disposition, Angelenos can revel in the warm, golden afternoons and clear skies, a delightful contrast to the preceding months that averaged closer to 55%. As autumn approaches, the city’s sunny reputation shines brighter than ever, inviting residents and visitors alike to embrace the outdoors before the cooler months set in.

Percentage of Sunny Days in September in Los Angeles

The chart illustrates the percentage of sunny days in Los Angeles 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 Los Angeles experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec62%65%69%54%55%68%68%72%74%68%69%49%
Data source: Los Angeles September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Los Angeles in September

As summer fades into autumn, September in Los Angeles brings a noticeable shift in daylight duration. With 12 hours of daylight, the city experiences a slight decrease from the 14 hours enjoyed during the peak summer months of June and July. This gradual transition reflects the overall trend of diminishing daylight as the year progresses; from a vibrant 14 hours at its height in mid-summer, the days now begin to shorten towards the cozy hours of fall. Following the warmth of summer, September strikes a balance, offering just enough sunlight to make the most of the pleasantly warm days before the shorter daylight hours of October settle in. Whether it's enjoying golden-hued sunsets or the lingering warmth of early fall, September invites Angelinos to relish the beauty of each day.

Average Daylight Hours in Los Angeles for September

The chart illustrates the variation in daylight duration in Los Angeles throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 10m10h 58m11h 59m13h 2m13h 56m14h 21m14h 7m13h 20m12h 19m11h 17m10h 22m9h 55m
Data source: Los Angeles daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Los Angeles

As summer gives way to autumn in Los Angeles, the September winds begin to whisper a different tune, with an average wind speed dropping to 1.9 m/s (4 mph). This decrease marks a subtle shift from the steadier breezes experienced in the preceding months. While the first half of the year enjoys consistent wind speeds hovering around 2.2 to 2.3 m/s, September introduces a gentler, calmer atmosphere, a preview of the season's transition. In fact, as temperatures begin to cool, the city's winds continue to ease off, culminating in an even lighter 1.8 m/s (4 mph) by November. This trend not only reflects the seasonal changes but also invites residents and visitors alike to savor the serene, sun-drenched days that characterize the tail end of summer.

Average September Wind Speed in Los Angeles

The chart displays monthly wind speed patterns in Los Angeles, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.22.12.22.32.32.32.12.11.9 m/s2.01.82.0
Data source: Los Angeles September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Los Angeles Compares to Other Months

The weather in Los Angeles 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 Los Angeles and find detailed weather information for every month.

In September, the weather is generally warm, with temperatures ranging from a mild 13°C (55°F) at night to a sweltering 45°C (113°F) during the day, accompanied by very low precipitation at only 3 mm and no rainy days. The humidity sits at a comfortable 68%. In contrast, January experiences much cooler temperatures, with a minimum of 3°C (37°F), an average of 13°C (57°F), and a maximum of 31°C (89°F). This month also sees significantly more rainfall, totaling 71 mm over five days, while the humidity levels rise slightly to 74%. For a more detailed look at January weather, you can check Los Angeles weather in January.

In comparing the weather of September and February, it's evident that September offers much warmer conditions, with average daytime temperatures reaching a pleasant 23°C (74°F), peaking at a scorching 45°C (113°F) on hot days. In stark contrast, February presents a cooler climate, with an average temperature of 14°C (57°F) and maximums around 32°C (89°F). Additionally, February experiences significantly more precipitation, totaling 55 mm (2.2 in) over about five rainy days, while September remains dry with no recorded precipitation. The humidity also varies slightly, being higher in February at 79% compared to 68% in September. For a detailed look at February's weather, you can visit Los Angeles weather in February.

September and March present contrasting weather patterns. In September, temperatures range from a mild 13°C (55°F) to a sizzling maximum of 45°C (113°F), with an average of 23°C (74°F), and it typically remains dry with only 3 mm (0.1 in) of precipitation over the course of the month. In contrast, March experiences cooler conditions with a minimum temperature of 4°C (40°F) and an average of 15°C (59°F), peaking at 31°C (88°F). Additionally, March is significantly wetter, accumulating 70 mm (2.8 in) of precipitation over about 8 days, leading to a higher humidity level of 75%. For more details, you can check the Los Angeles weather in March.

In September, the weather is typically warmer, with average temperatures around 23°C (74°F) and a maximum soaring up to 45°C (113°F), while experiencing minimal rainfall with just 3 mm (0.1 in) over the course of the month. In contrast, April sees cooler temperatures, averaging 18°C (64°F), with a maximum of 37°C (99°F), and is characterized by a slightly higher precipitation level of 19 mm (0.7 in) over two days. Despite both months having similar humidity levels (68% in September and 70% in April), the overall feel is quite different, making September warmer and drier compared to the more temperate and occasionally wetter April. For more detailed insights, check out Los Angeles weather in April.

In comparing the weather of September and May, we see distinct contrasts. September boasts higher temperatures, with a minimum of 13°C (55°F) and an average of 23°C (74°F), peaking at a sweltering 45°C (113°F). The month is characterized by minimal precipitation, averaging only 3 mm (0.1 in) with no rainy days, and a humidity level of 68%. In contrast, May experiences milder conditions, with temperatures ranging from a minimum of 9°C (48°F) to an average of 19°C (66°F) and a maximum of 35°C (96°F). May also has a higher precipitation level, totaling 12 mm (0.5 in) over three days, along with slightly elevated humidity at 70%. For more detailed insights on the weather during this month, you can check Los Angeles weather in May.

In comparing the weather patterns of September and June, both months exhibit relatively mild temperatures, with September enjoying a higher average temperature of 23°C (74°F) compared to June's average of 21°C (70°F). The maximum temperature also peaks significantly in September at 45°C (113°F), contrasting with June's maximum of 38°C (100°F). Additionally, both months experience minimal precipitation, recording just 3 mm (0.1 in) with no rain days. Humidity levels are slightly lower in September at 68%, compared to June’s humidity of 72%. For more detailed statistics, you can check out Los Angeles weather in June.

In comparing the weather between September and July, we see some subtle differences. September offers slightly cooler temperatures, with minimums around 13°C (55°F) compared to July's minimum of 15°C (60°F). The average temperatures remain quite similar, with September averaging 23°C (74°F) and July at 24°C (75°F). Interestingly, both months can reach the same maximum temperature of 45°C (113°F), but September experiences a bit more humidity at 68% versus July’s 73%. Precipitation levels are comparable as well, with September recording 3 mm (0.1 in) and July closely trailing at 2 mm (0.1 in), both having no rainy days. For a more detailed look at July's weather, you can check out Los Angeles weather in July.

In comparing the weather of September to that of August, September exhibits slightly cooler temperatures with a minimum of 13°C (55°F) and an average of 23°C (74°F), while August shows a minimum of 15°C (60°F) and an average of 24°C (76°F). The maximum temperature in September reaches 45°C (113°F), significantly higher than August's maximum of 39°C (102°F). Both months see minimal precipitation, with September receiving just 3 mm (0.1 in) and August recording 2 mm (0.1 in), and neither month experiences any rainy days. Humidity levels are similar, with September at 68% and August slightly higher at 69%. For more detailed information, check out Los Angeles weather in August.

In comparing the weather between September and October, we see a noticeable shift in temperatures and precipitation patterns. September features warmer days with an average temperature of 23°C (74°F) and a maximum that can soar to 45°C (113°F), while October cools down slightly, with an average of 21°C (70°F) and a maximum of 40°C (105°F). Precipitation also increases in October, with 8 mm (0.3 in) recorded over just one day, compared to September’s dry conditions with no recorded rainfall. Humidity remains relatively stable, around 68% in September and dipping slightly to 67% in October. For more specific details on October weather patterns, you can visit Los Angeles weather in October.

In comparing the weather between September and November, it's clear that September is characterized by much warmer temperatures, with averages reaching around 23°C (74°F) and maximums soaring to 45°C (113°F). This month experiences minimal precipitation, recording just 3 mm with no rainy days, and maintaining a consistent humidity level of 68%. Conversely, November brings a notable drop in temperature, with an average of 17°C (63°F) and maximums of 34°C (94°F). It also sees increased precipitation at 17 mm over one rainy day, while humidity remains steady at 68%. For more detailed insights into the weather conditions, you can check out Los Angeles weather in November.

September weather is characterized by warm temperatures, with daily averages around 23°C (74°F) and maximums soaring up to 45°C (113°F). The month is quite dry, receiving minimal precipitation of just 3 mm and experiencing no rainy days, while humidity hovers around 68%. In contrast, December brings significantly cooler conditions, with average temperatures dropping to 13°C (57°F) and highs reaching only 28°C (83°F). This month experiences more rainfall, receiving 76 mm over five rainy days, and the humidity increases slightly to 71%. For more details on December weather, visit Los Angeles weather in December.

Compare Los Angeles's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Los Angeles

In September, Los Angeles enjoys a delightful transition into fall, marked by warm temperatures averaging around 23°C (74°F) and a noticeable lack of precipitation—with no rain days to speak of. This month often stands out from the hotter summer months, as it presents a more comfortable climate with lower humidity levels, making it ideal for outdoor activities and exploration. With maximum temperatures soaring up to 45°C (113°F), it's a time to relish the warm days while enjoying the clear skies. For a comprehensive overview of what to expect throughout the year, be sure to check the detailed insights at Los Angeles Climate.