September Weather in Chattanooga, United States

Last updated: February 24, 2025

September in Chattanooga, United States presents a delightful blend of warmth and occasional rainfall, making it a unique month for residents and visitors alike. With maximum temperatures reaching a sizzling 37°C (98°F) and an inviting average of 24°C (75°F), the days are perfect for outdoor activities. However, the evenings can cool down to a minimum of 9°C (48°F), offering a refreshing break from the daytime heat. The month also sees about 106 mm (4.2 in) of precipitation spread over 8 days, contributing to a humidity level of 64%, which can accentuate the warm sensations. Enjoy the vibrant atmosphere of early autumn while embracing the fluctuating weather patterns that characterize Chattanooga in September!

September Temperature in Chattanooga

In September, Chattanooga transitions from the summer heat into the crisp beginnings of autumn, displaying a temperature range that highlights this shift. With minimum temperatures around 9°C (48°F) and average highs reaching 24°C (75°F), the month offers a perfect blend of warmth and coolness. As the maximum temperatures can still climb up to a sizzling 37°C (98°F), residents and visitors alike can bask in the lingering summer sun while enjoying the refreshing mornings and evenings. This dynamic temperature profile makes September an ideal time for outdoor activities, as the cooler weather invites exploration, while the warmth allows for leisurely days spent soaking in the natural beauty of the region.

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

The chart illustrates September temperature patterns in Chattanooga, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec434854607076797874645046
Data source: Temperature data for Chattanooga 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 Chattanooga

In Chattanooga, September marks a distinct transition in weather, as the region experiences an average precipitation of 106 mm (4.2 in) over just 8 days. This month often signals a tapering of summer rains, with a noticeable decline from the heavier downpours of August, which recorded similar rainfall but over a longer period of 14 days. The trend reflects a gradual shift towards autumn, where precipitation becomes less frequent yet maintains a steady volume. This pattern sets the stage for the cooler months ahead, as October brings a slight increase to 133 mm (5.2 in), hinting at the changing season without overwhelming the residents with wet weather. Overall, September's rainfall continues to play a vital role in preparing the landscape for fall's array of colors while ensuring that the air remains fresh and revitalizing.

September Precipitation Trends in Chattanooga

The chart displays monthly precipitation patterns in Chattanooga, 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.
JanFebMarAprMayJunJulAugSepOctNovDec991711691569612010612110613372139
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Chattanooga

In September, Chattanooga experiences a noticeable drop in humidity, averaging 64%, which marks one of the lowest levels for the year. This decrease follows a trend seen throughout the summer, with humidity levels gradually falling from a humid 78% in July and a notably drier 67% in August. The transition into fall begins to shape a more comfortable atmosphere, providing a refreshing change before the humidity levels creep back up in October. Overall, September serves as a pivotal month, bridging the gap between the sultry summer and the crisp, cooler air of autumn, making it an ideal time to enjoy outdoor activities in the scenic Tennessee landscape.

September Average Humidity in Chattanooga

This chart illustrates the average monthly humidity levels in Chattanooga, 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.
JanFebMarAprMayJunJulAugSepOctNovDec87%87%85%82%83%82%78%67%64%75%87%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Chattanooga

As September rolls into Chattanooga, residents can anticipate a UV Index of 9, placing it in the very high exposure category with a burn time of just 15 minutes. This trend reflects a slight dip from the extreme levels seen during the summer months of June, July, and May, when the UV Index peaked at 11. However, September still necessitates caution as the decreasing sunlight gives way to cooler days. As autumn approaches, it's vital to remain vigilant about sun protection, despite the transitional weather. For more detailed insights and daily updates, check out the Chattanooga UV Index.

Maximum UV Index Levels in Chattanooga for September

The chart shows the monthly maximum UV Index (UVI) for Chattanooga 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.
JanFebMarAprMayJunJulAugSepOctNovDec46810111111109753
Data source: Chattanooga 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 Chattanooga

As summer gives way to autumn, September in Chattanooga, United States, enjoys a wholesome bounty of sunshine with an impressive 276 hours of radiant daylight. This marks a gentle decline from the peak of 317 hours seen in July, yet it's significantly more than the dreary span of winter months like January, which only offers 146 hours. The trend culminates from the early bursts of spring in March with 217 hours, steadily escalating through the warmth of summer, showcasing Chattanooga's abundant sunlight that invites both residents and visitors to bask in the lingering warmth before the cooler October days set in with 253 hours. As daylight slightly diminishes, September still promises a vibrant tapestry of sunshine, making it a perfect time for outdoor adventures.

Monthly Sunshine Duration in Chattanooga: September Highlighted

The September sunshine duration represents the total number of hours Chattanooga 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.
JanFebMarAprMayJunJulAugSepOctNovDec146h153h217h265h302h300h317h305h276h253h226h168h
Data source: Chattanooga September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Chattanooga During September

In Chattanooga, September marks a noticeable upswing in the likelihood of sunny weather, boasting a 49% chance of sunshine—one of the higher percentages for the year. This improvement comes after a summer season characterized by relatively lower chances of sunny days, peaking in July and August at just 39% and 34%, respectively. As we transition into autumn, September reflects a welcome shift that closely aligns with the sunny disposition seen in April. This trend not only brightens the month but also makes it an ideal time for outdoor activities, with clearer skies often inviting residents and visitors alike to savor the beauty of the changing seasons.

Percentage of Sunny Days in September in Chattanooga

The chart illustrates the percentage of sunny days in Chattanooga 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 Chattanooga experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec36%38%36%52%31%37%39%35%49%36%57%37%
Data source: Chattanooga September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Chattanooga in September

As September dawns in Chattanooga, the days begin to gradually shorten, offering around 12 hours of daylight. This marks a subtle shift from the vibrant summer months of June and July, which basked in 14 hours of sunshine, creating an atmosphere of warmth and long outdoor evenings. In August, daylight starts to wane just a bit, settling at 13 hours, as nature begins its slow transition toward fall. The trend continues into September, where daylight is reduced, hinting at the approach of shorter days in October with 11 hours of sunlight. This gradual decrease signals a seasonal change, inviting residents to embrace crisp air and cooler temperatures while still enjoying ample daylight for outdoor activities.

Average Daylight Hours in Chattanooga for September

The chart illustrates the variation in daylight duration in Chattanooga throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 5m10h 55m11h 59m13h 5m14h14h 27m14h 12m13h 23m12h 20m11h 15m10h 18m9h 49m
Data source: Chattanooga daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Chattanooga

As September sweeps through Chattanooga, a gentle shift in the wind can be felt, marking the transition from the sultry summer months to the crispness of fall. With an average wind speed of 1.8 m/s (4 mph), the breezes are mild and refreshing, reminiscent of the soft whispers of autumn approaching. Notably, this slight increase from August's once languid 1.6 m/s (4 mph) reflects a burgeoning change in the season, pushing the city towards cooler days ahead. The wind picks up ever so slightly in October, suggesting a gradual yet welcome shift in the air as it prepares residents for the heart of fall.

Average September Wind Speed in Chattanooga

The chart displays monthly wind speed patterns in Chattanooga, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.72.82.52.42.11.81.61.8 m/s2.12.32.7
Data source: Chattanooga September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Chattanooga Compares to Other Months

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

September and January exhibit stark contrasts in weather conditions. In September, temperatures vary significantly, with a minimum of 9°C (48°F) and an average high of 24°C (75°F), reaching peaks of 37°C (98°F). The month experiences 106 mm (4.2 in) of precipitation over eight days, with a relative humidity of 64%. In contrast, January offers a much cooler climate, featuring a minimum temperature of -13°C (9°F) and an average of 6°C (43°F), with a maximum of 24°C (75°F)—notably similar to September's max but much less frequent due to the cold averages. Precipitation in January is slightly lower at 99 mm (3.9 in), occurring over ten days, accompanied by higher humidity at 87%. For more detailed insights on January weather, you can check Chattanooga weather in January.

September and February present stark contrasts in weather characteristics. September boasts a warm average temperature of 24°C (75°F), with daytime highs reaching up to 37°C (98°F), coupled with a moderate humidity level of 64%. However, it also experiences significant precipitation, totaling 106 mm (4.2 in) over approximately 8 days. In contrast, February sees much cooler temperatures, with an average of just 9°C (48°F) and nighttime lows dropping to -7°C (20°F). This month is marked by higher precipitation at 171 mm (6.7 in) occurring over 14 days and elevated humidity of 87%. To explore more about February weather specifics, you can check Chattanooga weather in February.

September and March present contrasting weather patterns. In September, temperatures range from a comfortable 9°C (48°F) at night to a hot 37°C (98°F) during the day, with an average of 24°C (75°F). The month experiences about 106 mm (4.2 in) of rain over 8 days, and the humidity averages around 64%. In contrast, March is cooler, with nighttime lows reaching -6°C (22°F) and daytime highs peaking at 29°C (84°F), averaging 12°C (54°F). It is also wetter, with total precipitation of 169 mm (6.7 in) across 13 days and higher humidity levels at 85%. For more specifics on March weather, visit Chattanooga weather in March.

When comparing the weather in September and April, notable differences emerge in temperature and precipitation. September experiences a warmer climate, with average temperatures reaching 24°C (75°F) and highs soaring up to 37°C (98°F). In contrast, April has cooler temperatures, with an average of 16°C (60°F) and a maximum of 30°C (87°F). Precipitation levels are higher in April, totaling 156 mm (6.2 in) over about 10 days, compared to September's 106 mm (4.2 in) spread across 8 days. Additionally, April tends to be more humid, with a humidity level of 82%, while September's humidity sits at 64%. For more detailed insights, you can check out Chattanooga weather in April.

September and May exhibit distinct weather characteristics, reflecting the transition between summer and autumn. In September, temperatures range from a minimum of 9°C (48°F) to a maximum of 37°C (98°F), with an average of 24°C (75°F) and a relatively moderate humidity level of 64%. The month experiences approximately 106 mm (4.2 in) of precipitation over 8 days. In contrast, May tends to be cooler, with temperatures ranging from 4°C (39°F) to 34°C (93°F) and an average of 21°C (70°F). The humidity is notably higher at 83%, and it experiences around 96 mm (3.8 in) of precipitation over 10 days. For more detailed information about the weather in May, you can check out Chattanooga weather in May.

When comparing the weather in September and June, both months exhibit warm average temperatures, hovering around 24°C (75°F) for September and slightly higher at 24°C (76°F) for June. However, September can experience more extreme heat, with maximum temperatures reaching up to 37°C (98°F), compared to June's high of 34°C (94°F). Precipitation is more frequent in June, with rainfall occurring on 13 days totaling 120 mm (4.7 in), while September sees slightly less rain over 8 days, accumulating to 106 mm (4.2 in). Additionally, June's humidity is noticeably higher at 82%, compared to September's 64%, contributing to the overall feel of the weather. For more details, you can visit Chattanooga weather in June.

In comparing the weather between September and July, September tends to be milder, with minimum temperatures dropping to 9°C (48°F) compared to 16°C (61°F) in July. Both months can reach a maximum of 37°C (98°F), but September boasts a more comfortable average temperature of 24°C (75°F) versus July's warmer average of 26°C (80°F). Precipitation levels are identical at 106 mm (4.2 in), but July experiences more rainy days (14 days) compared to September's 8 days, contributing to higher humidity in July at 78%, while September's humidity is relatively lower at 64%. For more details on July weather in Chattanooga, you can check out Chattanooga weather in July.

In comparing the weather between September and August, we can see notable differences in temperature and precipitation patterns. September features a wider temperature range, with minimums dropping to 9°C (48°F) and maximums soaring to 37°C (98°F), while August remains warmer, with minimums around 15°C (60°F) and a maximum of 35°C (96°F). Precipitation is slightly lower in September at 106 mm (4.2 in) over 8 days, compared to August’s 121 mm (4.8 in) over 14 days, indicating that September might be relatively drier. Humidity levels in August are marginally higher at 67%, while September averages around 64%. For a detailed look at August weather, you can visit Chattanooga weather in August.

September and October present a notable shift in weather patterns. September enjoys warm temperatures, with a minimum of 9°C (48°F) and an average peak of 37°C (98°F); however, it also brings a fair amount of precipitation at 106 mm (4.2 in) over eight days. In contrast, October sees a drop in minimum temperatures to -2°C (29°F) while still reaching a maximum of 37°C (99°F). The month also experiences increased humidity at 74% and slightly higher precipitation of 133 mm (5.2 in) over ten days. This transition signifies a move from the warmth of late summer to the cooler days of autumn. For more detailed insights, you can explore Chattanooga weather in October.

September and November present distinct contrasts in weather patterns. In September, temperatures range from a minimum of 9°C (48°F) to a maximum of 37°C (98°F), with an average of 24°C (75°F). This month experiences significant precipitation of 106 mm (4.2 in) over about 8 days, coupled with a moderate humidity level of 64%. In contrast, November brings cooler temperatures, with a minimum of -6°C (21°F) and a maximum of 26°C (79°F), averaging around 10°C (50°F). November also sees reduced precipitation at 72 mm (2.8 in) spread over the same 8 days, but the humidity is notably higher at 87%. For more details on the November climate, you can check Chattanooga weather in November.

In September, the weather tends to be warm and relatively humid, with average temperatures around 24°C (75°F) and maximums reaching up to 37°C (98°F). This month sees about 106 mm (4.2 in) of rainfall over approximately 8 days. In contrast, December brings much cooler conditions, with average temperatures dropping to 8°C (46°F) and minimums plummeting to -8°C (18°F). The precipitation slightly increases to 139 mm (5.5 in) over 10 days, and humidity rises significantly to 88%. For more detailed information about December weather, you can visit Chattanooga weather in December.

Compare Chattanooga's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Chattanooga

As summer transitions to autumn in Chattanooga, September showcases a delightful change in weather. The warm afternoons can still be enjoyed, with temperatures peaking around 37°C, yet the cooler mornings offer a refreshing contrast, dropping to a pleasant 9°C. Rainfall is generally moderate, with about 106 mm spread over roughly eight days, contributing to the region's vibrant changing foliage. The humidity level hovers at 64%, making the air feel comfortable during outdoor activities. Overall, September stands out as a month of balance, providing a blend of warmth and relief that differentiates it from both the sweltering heat of summer and the chill of fall. For more detailed insights, visit Chattanooga Climate.