September Weather in New Orleans, United States

Last updated: February 24, 2025

September in New Orleans brings a blend of warmth and humidity, with average temperatures hovering around 27°C (80°F). Daytime highs can reach a sweltering 34°C (94°F), while nights cool down to a pleasant 17°C (64°F). This month is marked by 79% humidity, contributing to a sticky atmosphere. Rainfall is frequent, with 15 rainy days accumulating about 147 mm (5.8 inches) of precipitation, often in the form of brief, heavy showers. Overall, visitors should be prepared for a warm, humid environment with occasional rain as they explore the vibrant culture of this iconic city.

September Temperature in New Orleans

September in New Orleans marks a transition to slightly cooler temperatures after the sweltering summer months. With minimums settling around 17°C (64°F) and an average of 27°C (80°F), the city starts to feel more comfortable compared to the peak summer heat. While the maximum temperature can still reach a hot 34°C (94°F), the overall trend indicates a gradual easing of the intense summer warmth. This month serves as a delightful bridge into fall, offering residents and visitors alike a chance to enjoy the vibrant culture and outdoor festivities in more pleasant conditions. As September unfolds, the unique charm of New Orleans becomes even more inviting, perfect for exploring its lively streets and rich heritage.

September Weather in New Orleans: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in New Orleans, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec556065697781828280746258
Data source: Temperature data for New Orleans 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 New Orleans

In September, New Orleans experiences a significant amount of rainfall, with an average precipitation of 147 mm (5.8 in) occurring over 15 days. This marks a slight decrease from the heavy downpours of August, which saw a staggering 273 mm (10.8 in) over 23 days. The trend of increased precipitation during the summer months gives way to a moderated yet consistent rainfall pattern as fall approaches, indicating the city's transition from the late summer wet season. The rainfall in September, while still substantial, sets the stage for drier months ahead, particularly as October typically sees a further decline to 133 mm (5.2 in) over just 12 days. This shifting climate not only reflects the seasonal cycle but also underscores the resilience of New Orleans as it navigates the unique challenges posed by its humid subtropical environment.

September Precipitation Trends in New Orleans

The chart displays monthly precipitation patterns in New Orleans, 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.
JanFebMarAprMayJunJulAugSepOctNovDec90968711314421821927314713358101
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in New Orleans

In September, New Orleans experiences a relative humidity of 79%, slightly higher than the summer months of July and August, which sit at 74% and 73%, respectively. This upward trend reflects the city's tendency to maintain high humidity levels throughout the year, with values consistently hovering around the 80% mark in the cooler months of January, February, April, and November. Notably, December sees humidity peak at 84%, suggesting that while September offers a brief respite from the summertime lows, the air remains thick with moisture as autumn approaches. Overall, the gradual shifts in humidity highlight New Orleans' characteristic subtropical climate, where warmth and humidity continue to linger even as fall sets in.

September Average Humidity in New Orleans

This chart illustrates the average monthly humidity levels in New Orleans, 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.
JanFebMarAprMayJunJulAugSepOctNovDec81%81%79%81%77%74%74%73%79%77%81%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in New Orleans

As summer transitions into fall, September in New Orleans sees a UV Index of 10, placing it in the very high exposure category, with a burn time of just 15 minutes. This slight decline from the intense levels of summer indicates a gradual easing of solar intensity, yet caution remains essential for sun exposure. The trend showcases a consistent pattern of elevated UV levels from April through August, followed by a minor decrease as the year progresses. As outdoor activities abound, it's crucial to stay informed and protected. For detailed information and planning, check out the New Orleans UV Index.

Maximum UV Index Levels in New Orleans for September

The chart shows the monthly maximum UV Index (UVI) for New Orleans 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.
JanFebMarAprMayJunJulAugSepOctNovDec589111112121110965
Data source: New Orleans 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 New Orleans

As summer transitions into autumn, September in New Orleans enjoys a delightful 279 hours of sunshine. This marks a slight dip from the sun-drenched months of July and August, which each basked in over 300 hours of sun. However, it still stands as a robust month compared to the colder winter months, such as January and December, which see just 180 and 220 hours respectively. The cooling heat of September, combined with abundant sunshine, creates the perfect backdrop for enjoying the vibrant culture and outdoor activities of the city, while hinting at the splendid golden hues to come in October. This balanced light offers a serene transition, ensuring that the charm of New Orleans remains captivating well into the fall.

Monthly Sunshine Duration in New Orleans: September Highlighted

The September sunshine duration represents the total number of hours New Orleans 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.
JanFebMarAprMayJunJulAugSepOctNovDec180h195h271h280h320h298h307h306h279h287h257h220h
Data source: New Orleans September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in New Orleans During September

In September, New Orleans enjoys a 47% chance of sunny weather, positioning it favorably compared to the sweltering summer months. After a stretch of diminished sunlight, with July and August dropping to just 26% and 31% respectively, September marks a notable rebound as the city transitions into the fall season. This gradual increase in sunshine is reflective of the overall trend where autumn months like October and November continue to rise, with October also seeing a 49% chance. Such patterns suggest that visitors can expect a more pleasant climate as the sultry summer heat wanes, making September an enticing time to experience the vibrant culture of New Orleans under clearer skies.

Percentage of Sunny Days in September in New Orleans

The chart illustrates the percentage of sunny days in New Orleans 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 New Orleans experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec50%37%39%49%37%28%26%31%47%49%64%43%
Data source: New Orleans September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in New Orleans in September

As summer fades and September rolls into New Orleans, the city basks in 12 hours of daylight, a slight decline from the peak of 14 hours in June. This steady transition marks the end of the longer, sun-drenched days of the season, bringing a gentle shift towards the shorter days of autumn. The pattern showcases a gradual reduction in daylight, with longer hours reaching their zenith in May and June, before tapering off as the year progresses. Visitors and locals alike can relish the lingering warmth of summer as they enjoy the vibrant energy of the city, while also embracing the subtle invitation of autumn that September brings.

Average Daylight Hours in New Orleans for September

The chart illustrates the variation in daylight duration in New Orleans throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 27m11h 8m12h12h 54m13h 39m14h 1m13h 49m13h 9m12h 17m11h 24m10h 37m10h 14m
Data source: New Orleans daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in New Orleans

In September, New Orleans experiences a subtle decline in wind speed, with an average of 3.1 m/s (7 mph). This marks a continuation of the trend observed throughout the summer months, where winds steadily decrease from 4.6 m/s (10 mph) in March to the more languid breezes typical of late summer. The gentle winds of September create a warm and inviting atmosphere in the city, perfect for outdoor activities and festivals. As autumn approaches, the shift to a milder pace in the wind serves as a gentle reminder of the changing seasons, while still embracing the vibrant energy that is uniquely New Orleans.

Average September Wind Speed in New Orleans

The chart displays monthly wind speed patterns in New Orleans, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.24.54.64.24.43.52.43.33.1 m/s3.33.23.6
Data source: New Orleans September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in New Orleans Compares to Other Months

The weather in New Orleans 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 New Orleans and find detailed weather information for every month.

September and January present a striking contrast in weather. In September, temperatures are much warmer, with averages around 27°C (80°F) and highs reaching up to 34°C (94°F), accompanied by significant rainfall totaling 147 mm (5.8 in) over 15 days. Meanwhile, January experiences much cooler conditions, with average temperatures dipping to 13°C (55°F) and lows plummeting to -5°C (23°F), while rainfall is less frequent and totals only 90 mm (3.5 in) across 8 days. Humidity remains high in both months, reaching 79% in September and slightly rising to 81% in January, but the overall feel of the weather is vastly different. For a detailed look at January conditions, you can check out New Orleans weather in January.

September and February present contrasting weather experiences. In September, temperatures range from a mild 17°C (64°F) at night to a sizzling 34°C (94°F) during the day, with an average of 27°C (80°F). However, the month also sees considerable rainfall, totaling 147 mm (5.8 in) over about 15 days, contributing to the high humidity of 79%. In stark contrast, February brings much cooler weather, with temperatures ranging from a low of -3°C (26°F) to a comfortable high of 26°C (80°F), averaging around 15°C (60°F). While precipitation is lower at 96 mm (3.8 in) over 12 days, the humidity remains similar at 81%. For those interested in a closer look at February weather, you can refer to this link: New Orleans weather in February.

When comparing the weather in September and March, there are notable differences in temperature and precipitation. September tends to be much warmer, with average temperatures ranging from 17°C (64°F) at night to a high of 34°C (94°F) during the day, while March offers cooler conditions, with temperatures ranging from a chilly 2°C (36°F) at night to a maximum of 29°C (84°F). Additionally, September experiences significantly more rainfall, totaling 147 mm (5.8 in) over approximately 15 days, compared to March's 87 mm (3.4 in) over about 10 days. Despite the variations in temperature and precipitation, both months share a similar humidity level of 79%. For more detailed insights, you can check the New Orleans weather in March.

When comparing the weather in September and April, we see a notable difference in temperature and precipitation patterns. September tends to be warmer, with average temperatures ranging from a minimum of 17°C (64°F) to a maximum of 34°C (94°F), while April presents cooler conditions with temperatures ranging from 9°C (48°F) to 29°C (85°F). Additionally, September experiences more precipitation, with 147 mm (5.8 in) over 15 days, compared to April's 113 mm (4.5 in) across 11 days. Both months have similar humidity levels, with September at 79% and April slightly higher at 81%. For more detailed information, check out New Orleans weather in April.

When comparing the weather in September and May, both months exhibit warm temperatures and a similar level of precipitation. September averages a higher temperature range, with minimums of 17°C (64°F) and maximums of 34°C (94°F), while May has slightly cooler averages, with minimums of 14°C (58°F) and maximums reaching 33°C (91°F). Both months experience notable humidity, with September slightly higher at 79% compared to 77% in May. Interestingly, September sees a bit more rainfall, with 147 mm (5.8 in) over 15 days, compared to May's 144 mm (5.7 in) over 13 days. For a more detailed look at the weather in May, check out New Orleans weather in May.

In comparing the weather of September and June, both months experience similar average temperatures, hovering around 27°C (81°F). However, September features slightly cooler minimum temperatures at 17°C (64°F) compared to June's 21°C (69°F). Rainfall is another distinguishing factor; September sees a total precipitation of 147 mm (5.8 in) over 15 days, while June is wetter, with 218 mm (8.6 in) across 18 days. Additionally, September has a higher humidity level at 79%, in contrast to June's 74%. For more detailed information about June weather, check out New Orleans weather in June.

When comparing the weather between September and July, several notable differences emerge. September typically experiences slightly cooler temperatures, with a minimum of 17°C (64°F) and an average of 27°C (80°F), compared to July’s higher minimum of 23°C (75°F) and average of 28°C (83°F). Despite both months reaching a maximum of 34°C (94°F), September is characterized by a higher overall humidity level of 79%, while July’s humidity is somewhat lower at 74%. However, July sees more precipitation, totaling 219 mm (8.6 in) over 22 days, compared to September's 147 mm (5.8 in) over 15 days. For a deeper dive into the specifics of July weather, you can explore New Orleans weather in July.

In comparing the weather of September and August, September experiences slightly cooler temperatures, with an average of 27°C (80°F) compared to August's 28°C (83°F). While both months reach a maximum of 34°C (93-94°F), September's minimum temperature is noticeably lower at 17°C (64°F), contrasting with August's warmer minimum of 23°C (74°F). Additionally, September sees a decrease in rainfall, with 147 mm (5.8 in) recorded over 15 days, while August is much wetter, accumulating 273 mm (10.8 in) over 23 days. Humidity levels are higher in September at 79%, compared to August's 73%. For more details, check out the New Orleans weather in August.

In comparing September and October, September tends to be notably warmer, with average temperatures reaching 27°C (80°F) and maximums climbing up to 34°C (94°F). Precipitation is also higher in September, averaging 147 mm (5.8 in) over 15 days. In contrast, October sees a drop in minimum temperatures to 8°C (47°F) and a decrease in the average to 23°C (74°F), making it feel much cooler overall. Additionally, October experiences slightly less rain, with 133 mm (5.2 in) over 12 days, and maintains a similar humidity level at 77%. For more details about the weather in October, you can visit New Orleans weather in October.

September's weather is characterized by warm temperatures, with averages around 27°C (80°F) and highs reaching up to 34°C (94°F), making it a lively month that often feels quite humid at 79%. However, it's also rainy, with around 147 mm (5.8 in) of precipitation spread over 15 days. In contrast, November brings much cooler conditions, with average temperatures dropping to 17°C (62°F) and maximums of 27°C (80°F). The month is drier, experiencing only 58 mm (2.3 in) of rain over 7 days, along with a slight increase in humidity to 81%. For more details on what to expect in November, check out New Orleans weather in November.

In September, the weather is warm and humid, with temperatures ranging from a minimum of 17°C (64°F) to a maximum of 34°C (94°F) and an average of 27°C (80°F). With 147 mm (5.8 in) of precipitation over 15 days, it is often a rainy month, characterized by a high humidity level of 79%. In contrast, December sees a significant drop in temperatures, with a minimum of 3°C (37°F), an average of 14°C (58°F), and a maximum of 26°C (80°F). Precipitation is lower at 101 mm (4.0 in) over 12 days, and humidity increases slightly to 84%. For more details on December weather, you can visit New Orleans weather in December.

Compare New Orleans's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in New Orleans

As summer transitions into fall, September in New Orleans showcases a vibrant shift in weather dynamics. With average temperatures settling around 27°C (80°F), the heat remains palpable, but the increased chance of rainfall—averaging about 15 days of precipitation—serves as a reminder that the sultry season is winding down. The humidity levels, lingering at 79%, continue to envelop the city, albeit with a hint of relief as the days grow shorter. This month stands out with a delicate balance between lingering summer warmth and the anticipatory whispers of fall, making it a unique time to experience the city's atmosphere. For further insights into the changing climate, check out New Orleans Climate.