September Weather in Nantes, France

Last updated: February 26, 2025

September in Nantes, France, showcases a transition from summer to autumn, with temperatures ranging from a maximum of 34°C (93°F) to a minimum of 5°C (41°F). The average temperature settles comfortably at 17°C (63°F), offering pleasant days for exploring the city. However, September also brings some precipitation, with a total of 45 mm (1.8 in) spread across about 8 days, contributing to the region's lush, vibrant landscapes. Humidity levels hover around 75%, adding a slight chill to the evenings as the days grow shorter. Overall, September is a month of contrasting weather that captures the essence of Nantes' seasonal shifts.

September Temperature in Nantes

In September, Nantes begins to cool down from the summer heat while still enjoying pleasant weather. With minimum temperatures around 5°C (41°F), the month ushers in a refreshing change. The average temperature rises to 17°C (63°F), making it a comfortable time for outdoor activities and exploration. Though still reaching a maximum of 34°C (93°F) at times, the warmer days are often balanced with cooler evenings, offering a lovely transition into autumn. This month stands out as the perfect blend of lingering summer warmth and the crispness of approaching fall, inviting visitors to experience the city's vibrant atmosphere.

September Weather in Nantes: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Nantes, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec434548535965686763564846
Data source: Temperature data for Nantes 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 Nantes

In September, Nantes experiences a moderate amount of rainfall, with 45 mm (1.8 in) of precipitation spread over 8 days. This marks a slight decrease from the peak of summer, where August saw 42 mm (1.7 in), but with fewer rainy days. As the month transitions into autumn, the precipitation levels hint at the wetter months ahead, particularly October, which typically sees a significant increase to 83 mm (3.3 in). September's relatively mild conditions serve as a bridge, gently ushering in the more consistent rains that characterize the later fall months. With this gradual shift, the region prepares for the lush greenery that will thrive in response to the abundant autumnal showers.

September Precipitation Trends in Nantes

The chart displays monthly precipitation patterns in Nantes, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5166715164843642458379107
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Nantes

In Nantes, France, September marks a transitional shift in humidity levels as summer comes to a close. With an average humidity of 75%, the city experiences a slight increase from the drier months of July and August, which recorded 65% and 67%, respectively. This uptick signals the approach of autumn, where humidity levels begin to climb again, paving the way for the much wetter months ahead. As the year progresses, Nantes sees its highest humidity levels in winter, peaking at 90% in December, while the early months of the year remain consistently high. Overall, September serves as a bridge between the warmth of summer and the cooler, more humid seasons to come.

September Average Humidity in Nantes

This chart illustrates the average monthly humidity levels in Nantes, 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.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%84%83%81%75%65%67%75%85%88%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Nantes

As September rolls into Nantes, France, the UV Index reflects a slight decrease from the peak summer months, settling at 6—indicating a high exposure category. This means that outdoor enthusiasts can enjoy approximately 25 minutes of sun before the risk of burning increases. Compared to the very high levels of 8 and 9 witnessed in July and August, September offers a reprieve while still necessitating caution under the sun. The overall trend shows a gradual transition into autumn, with UV levels dropping as daylight hours shorten, yet it serves as a reminder that sun safety is essential year-round. For more detailed information on the UV Index throughout the year, check out Nantes UV Index.

Maximum UV Index Levels in Nantes for September

The chart shows the monthly maximum UV Index (UVI) for Nantes 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.
JanFebMarAprMayJunJulAugSepOctNovDec235689986522
Data source: Nantes 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 Nantes

As summer transitions into autumn, September in Nantes, France continues to bask in plenty of sunshine, with an impressive 331 hours of bright days. This month stands out as a vital bridge, tapering off from July's peak of 418 hours and August's 395 hours, reminding us that the warmth persists even as the days grow shorter. Indeed, as the city emerges from the sun-drenched peaks of summer, September maintains a significant share of sunlight that rivals the earlier months of the season. Following the trend, the sunny hours begin to decline, yet the relatively abundant light serves as an invitation to enjoy the last lingering moments of summer before the cooler October sets in with just 274 hours. Thus, September offers a delightful golden hour for both locals and visitors, striking a perfect balance between warmth and the crispness of fall.

Monthly Sunshine Duration in Nantes: September Highlighted

The September sunshine duration represents the total number of hours Nantes 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.
JanFebMarAprMayJunJulAugSepOctNovDec139h208h291h350h394h398h418h395h331h274h227h193h
Data source: Nantes September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Nantes During September

As summer fades into autumn, September in Nantes offers a promising mix of sunshine, boasting a 46% chance of clear skies. This slight increase from the summer months reflects a consistent trend, with the likelihood of sunny weather gradually rising from a low of 19% in January to a peak in April at 58%. While the warmth of July and August draws visitors looking for sun-soaked days, September presents a delightful opportunity for those eager to enjoy cooler temperatures combined with pleasant weather. This transitional month both signals the approaching fall while still holding on to the remnants of summer, allowing for a perfect blend of outdoor enjoyment under the sun.

Percentage of Sunny Days in September in Nantes

The chart illustrates the percentage of sunny days in Nantes 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 Nantes experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec19%29%47%58%35%40%42%44%46%46%40%30%
Data source: Nantes September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Nantes in September

As summer fades and autumn approaches, September in Nantes, France, welcomes a shift in daylight duration, offering about 12 hours of daylight. This marks a gradual decline from the sun-drenched days of July and August, which each basked in 15 hours of sunlight. Compared to the earlier months of the year, where daylight starts at a mere 8 hours in January and climbs steadily, September reflects a balance of light and shadows. The transition into autumn is evident as daylight begins to shorten, setting the stage for the cozy, cooler days of October, which will see daylight shrink to 10 hours. This rhythmic ebb and flow of daylight not only highlights the changing seasons but also invites residents and visitors to savor the splendor of Nantes during this beautifully transitional time.

Average Daylight Hours in Nantes for September

The chart illustrates the variation in daylight duration in Nantes throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 57m10h 17m11h 56m13h 38m15h 5m15h 50m15h 26m14h 8m12h 30m10h 49m9h 19m8h 32m
Data source: Nantes daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Nantes

As summer gives way to autumn, September in Nantes greets us with a gentle breeze, averaging 3.3 m/s (7 mph) – the calmest wind speed of the year. This subtle shift reflects a broader trend in the changing seasons, where the previous summer months recorded higher speeds, and the winds begin to mellow. Comparatively, June’s breezy 2.8 m/s (6 mph) hinted at the summer lull, while October brings a slight pickup to 3.7 m/s (8 mph), suggesting a gradual return to more robust gusts as the season progresses. The winds of September, though softer, create a serene atmosphere, perfectly complementing the vibrant autumnal hues emerging in the Nantes landscape.

Average September Wind Speed in Nantes

The chart displays monthly wind speed patterns in Nantes, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.14.73.94.04.62.83.83.73.3 m/s3.73.44.6
Data source: Nantes September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Nantes Compares to Other Months

The weather in Nantes 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 Nantes and find detailed weather information for every month.

September and January showcase striking contrasts in weather. In September, temperatures range from a cool 5°C (41°F) at night to a warm 34°C (93°F) during the day, with an average of 17°C (63°F). The month sees a moderate amount of rainfall, totaling 45 mm (1.8 in) over 8 days, accompanied by a humidity level of 75%. In contrast, January brings much colder conditions, with temperatures dropping to a minimum of -7°C (20°F) and peaking at only 16°C (61°F), averaging 6°C (43°F). Precipitation during this winter month is slightly higher at 50 mm (2.0 in) and occurs over 9 days, matched with a higher humidity level of 88%. For more specific details on January weather, check out Nantes weather in January.

In September, the weather is generally warm, with average temperatures around 17°C (63°F), peaking at a comfortable 34°C (93°F). The month experiences relatively low precipitation, with about 45 mm (1.8 in) over 8 days, and humidity levels are moderate at 75%. In contrast, February brings much colder temperatures, averaging 7°C (46°F), with lows dipping to -6°C (21°F) and highs reaching only 22°C (71°F). Precipitation in February increases to 66 mm (2.6 in) over 13 days, and humidity rises to 87%, creating a distinctly wetter and chillier atmosphere. For a more detailed look at February weather, visit Nantes weather in February.

In comparing the weather of September and March, we see notable differences in temperature and precipitation patterns. September typically offers a milder climate, with average temperatures around 17°C (63°F) and a maximum of 34°C (93°F), while March is cooler, averaging 9°C (49°F) with a maximum of 24°C (76°F) and a chilling minimum of -8°C (19°F). Additionally, March tends to be wetter, with 71 mm (2.8 in) of precipitation over 13 days compared to September's 45 mm (1.8 in) across 8 days. Both months experience relatively high humidity, with March being slightly more humid at 84% compared to September's 75%. For a detailed look at March's climate, you can check Nantes weather in March.

In comparing the weather of September and April, we see notable differences in both temperature and humidity. September boasts a wider temperature range, with minimums reaching 5°C (41°F) and maximums soaring up to 34°C (93°F), resulting in a pleasant average of 17°C (63°F). In contrast, April starts off cooler, featuring minimum temperatures as low as -3°C (27°F) and maximums that reach 27°C (80°F), contributing to a lower average of 12°C (53°F). Both months experience similar levels of precipitation, with September receiving 45 mm (1.8 in) and April slightly more at 51 mm (2.0 in), each seeing around 8 days of rain. Additionally, humidity levels in April are marginally higher at 83%, compared to September's 75%. For a closer look at what to expect, you can check Nantes weather in April.

September generally experiences warmer temperatures compared to May, with daily averages around 17°C (63°F) and maximums reaching up to 34°C (93°F). In contrast, May has a slightly cooler average of 15°C (59°F) and peaks at 31°C (88°F). Precipitation is more frequent in May, with about 64 mm (2.5 in) spread over 11 days, compared to September’s 45 mm (1.8 in) on 8 days. Humidity levels are also higher in May at 81% versus September’s 75%. For more details on May weather, check out Nantes weather in May.

When comparing the weather in September and June, we see some notable differences. September typically experiences a greater temperature range, with minimums around 5°C (41°F) and maximums peaking at 34°C (93°F), averaging 17°C (63°F). In contrast, June has slightly warmer temperatures, with minimums of 6°C (44°F) and maximums reaching up to 37°C (98°F), averaging 18°C (65°F). Precipitation levels are also higher in June, with 84 mm (3.3 in) spread over 11 days, compared to 45 mm (1.8 in) over 8 days in September. Both months share a humidity level of 75%, though the overall warmer weather in June often leads to a more humid feel. For more details on June weather, you can check out Nantes weather in June.

When comparing the weather in September and July, we see notable differences in temperature and humidity. September tends to be cooler, with a minimum temperature of 5°C (41°F) and an average of 17°C (63°F), while July is warmer, boasting a minimum of 9°C (48°F) and an average of 20°C (69°F). Additionally, July can reach higher maximum temperatures, peaking at 38°C (100°F) compared to September's max of 34°C (93°F). Precipitation is slightly higher in September with 45 mm (1.8 in) over 8 days, while July experiences 36 mm (1.4 in) over 7 days. Humidity levels are also higher in September at 75%, compared to July's 65%. For more detailed information on July weather, you can visit Nantes weather in July.

September weather shows a notable shift compared to August, with cooler minimum temperatures dropping to 5°C (41°F) from August's 8°C (47°F) and an average high of 34°C (93°F) compared to August's peak of 38°C (100°F). Despite a slight increase in precipitation to 45 mm (1.8 in) over 8 days, September maintains a higher humidity level at 75% versus August's 67%. For a more detailed view of August weather, you can explore Nantes weather in August.

September tends to be warmer compared to October, with average temperatures around 17°C (63°F) and occasional peaks reaching 34°C (93°F). In contrast, October's temperatures drop, with an average of 13°C (56°F) and maximums of 26°C (79°F). Additionally, October sees an increase in precipitation, measuring 83 mm (3.3 in) over 11 days, compared to September's 45 mm (1.8 in) across 8 days. The humidity also rises, reaching 85% in October compared to 75% in September, adding to the chillier feel of the month. For more details, visit Nantes weather in October.

September and November present contrasting weather conditions. In September, temperatures range from a mild 5°C (41°F) at night to a warm 34°C (93°F) during the day, with an average temperature of 17°C (63°F). The month sees less precipitation, totaling 45 mm (1.8 in) over 8 days and relatively moderate humidity at 75%. In stark contrast, November brings cooler temperatures, with a minimum of -3°C (26°F) and a maximum of 19°C (66°F), averaging 9°C (48°F). The month is wetter, with 79 mm (3.1 in) of rain falling on 11 days, and humidity rises to a notable 88%. For more insights, check out Nantes weather in November.

September and December present contrasting weather patterns that highlight the transition from late summer to winter. In September, temperatures range from a mild 5°C (41°F) at night to a warm average of 17°C (63°F) during the day, reaching highs of 34°C (93°F). The month sees relatively low precipitation, totaling 45 mm (1.8 in) over about 8 days, with humidity averaging 75%. In contrast, December experiences colder conditions, with temperatures dipping to a minimum of -3°C (27°F) and an average of only 8°C (46°F). This month is considerably wetter, accumulating 107 mm (4.2 in) of rainfall across approximately 15 days and accompanied by higher humidity levels at 90%. For more detailed information on the weather in December, you can check Nantes weather in December.

Compare Nantes's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Nantes

As summer transitions into autumn, September in Nantes brings a delightful change of pace. The warmth is still present, with occasional highs reminiscent of the summer months, yet the average temperature begins to drop, offering a refreshing escape from the sweltering heat. Rain becomes a frequent visitor, with more precipitation days compared to the drier summer months, although the overall amount remains modest. Humidity is palpable, creating that characteristic crispness in the air, perfect for enjoying the city's vibrant outdoor scenes. For a deeper dive into how September weather stacks up throughout the year, check out Nantes Climate.