September Weather in Cincinnati, United States

Last updated: February 24, 2025

September in Cincinnati, United States is marked by a tapestry of weather experiences, where daytime maximum temperatures can soar to a sweltering 35°C (95°F), while cooler nights dip to a refreshing 7°C (44°F). The average temperature hovers around a comfortable 21°C (71°F), creating an inviting atmosphere for outdoor activities. Rainfall also plays a role, with precipitation totaling 81 mm (3.2 in) over approximately 8 days, contributing to the lushness of the season. A backdrop of 73% humidity weaves through the month, adding a subtle warmth that enhances the vibrant urban and natural landscapes of Cincinnati. Enjoy this transition into fall as the city prepares for the colorful changes ahead!

September Temperature in Cincinnati

In September, Cincinnati transitions into early fall, boasting mild temperatures that invite outdoor activities. The month begins with a comfortable minimum of 7°C (44°F) and reaches an average of 21°C (71°F), peaking at a warm 35°C (95°F) on the hottest days. This noticeable warmth still lingers from summer, offering a pleasant contrast to the brisk coolness that follows in October. The decreasing temperatures mark a shift in seasons, but the vibrant atmosphere remains, with clear skies often dominating the early autumn days. As the month progresses, Cincinnatians can enjoy the delightful balance of summer's warmth and the fresh air of impending fall, making September one of the most enjoyable months of the year.

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

The chart illustrates September temperature patterns in Cincinnati, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec333745546674787571594439
Data source: Temperature data for Cincinnati 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 Cincinnati

In September, Cincinnati experiences a gentle transition toward fall, reflected in its precipitation patterns. With an average rainfall of 81 mm (3.2 in) over just 8 days, September showcases a slight decline in both rainfall and rain days compared to the moister summer months. This marks a shift from the consistent precipitation seen in the preceding months, such as June and July, which had higher totals of 131 mm (5.2 in) and 110 mm (4.3 in), respectively. As the city inches closer to autumn, the lighter precipitation contributes to a more comfortable climate, making it an ideal time for outdoor activities, while still hinting at the rainier conditions that are typical in the later months of the year.

September Precipitation Trends in Cincinnati

The chart displays monthly precipitation patterns in Cincinnati, 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.
JanFebMarAprMayJunJulAugSepOctNovDec8010713711912713111089819699110
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Cincinnati

In Cincinnati, September marks the end of the summer season, and the humidity dips to a comfortable 73%. This trend of decreasing humidity is evident as the city transitions from the sweltering summer months, where humidity peaked at 81% in July and 73% in August, to the more temperate autumn. Overall, the humidity levels in September are reflective of a broader yearly pattern, as Cincinnati experiences its highest levels during the winter months, with a staggering 88% in January and February. As fall approaches, the city gradually shifts to lower humidity levels, paving the way for crisp, refreshing days ahead.

September Average Humidity in Cincinnati

This chart illustrates the average monthly humidity levels in Cincinnati, 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%88%87%85%81%82%81%73%73%78%89%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Cincinnati

As summer fades into September, Cincinnati experiences a decline in the UV Index, dropping to 8, categorized as very high. This trend reflects a slight easing of sunlight intensity compared to the peak months of May through August, where the index hovered at 10. Despite this decrease, burn time remains short at just 15 minutes, underscoring the necessity for sun protection even as the season transitions. With the UV Index in September still notably high, it’s essential for residents and visitors alike to stay vigilant about sun safety. For more details on UV exposure trends, visit Cincinnati UV Index.

Maximum UV Index Levels in Cincinnati for September

The chart shows the monthly maximum UV Index (UVI) for Cincinnati 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.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098643
Data source: Cincinnati 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 Cincinnati

As summer fades, September in Cincinnati, United States, continues to bask in a generous 282 hours of sunshine, showcasing a delightful transition toward fall. This month retains a vibrant glow, albeit slightly diminishing from the peak of 348 hours in July and 321 hours in August. The sunny days linger, offering a perfect backdrop for outdoor activities and a chance to savor the fading warmth before the cooler months set in. Notably, sunshine hours have a clear upward trend from the chill of winter, where January sees a mere 122 hours. As the city gears up for October, the drop to 244 hours is gentle, hinting at a comforting continuity that characterizes Cincinnati's late summer and early autumn. Overall, September's rays symbolize not just warmth but the gradual embrace of fall, inviting residents to relish each sun-soaked moment.

Monthly Sunshine Duration in Cincinnati: September Highlighted

The September sunshine duration represents the total number of hours Cincinnati 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.
JanFebMarAprMayJunJulAugSepOctNovDec122h151h224h237h287h320h348h321h282h244h196h160h
Data source: Cincinnati September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Cincinnati During September

In Cincinnati, September marks a delightful transition into autumn, with a notable 56% chance of sunny weather—the highest probability for clear skies after April. This upward trend in sunshine is a welcome change from the summer months, where the likelihood dipped to 32% in May and peaked at 48% in July. As the city moves into fall, residents and visitors alike can enjoy a beautiful balance of warmth and clear days, making September an ideal month for outdoor activities and exploring the vibrant shades of early autumn. This positive shift in sunshine not only enhances the local landscape but also invites opportunities for fun and relaxation in the great outdoors.

Percentage of Sunny Days in September in Cincinnati

The chart illustrates the percentage of sunny days in Cincinnati 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 Cincinnati experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec29%26%46%50%32%37%48%41%56%38%48%35%
Data source: Cincinnati September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Cincinnati in September

As summer transitions into autumn in Cincinnati, September sees a shift in daylight duration, with the sun gracing the skies for 12 hours. This month's daylight is a comfortable step down from the peak 14 hours of June and July, reflecting the natural ebb of summer's warmth. With long, sunlit days still illuminating the early weeks of fall, Cincinnatians can savor the outdoors before the daylight gradually shortens to 11 hours in October. The noticeable decrease in daylight from the bustling summer months creates a beautiful backdrop for the changing leaves, making September a cherished bridge between seasons.

Average Daylight Hours in Cincinnati for September

The chart illustrates the variation in daylight duration in Cincinnati throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 45m10h 44m11h 58m13h 15m14h 19m14h 51m14h 34m13h 36m12h 23m11h 7m10h9h 26m
Data source: Cincinnati daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Cincinnati

As September breezes into Cincinnati, the average wind speed hovers around 2.9 m/s (6 mph), mirroring the gentle currents of October. This marks a slight uptick from the sultry depths of summer when July and August experienced their calmest winds, dropping to 2.3 m/s (5 mph) and 2.1 m/s (5 mph), respectively. The shift in wind patterns hints at the approaching autumnal change, as September's winds are notably more invigorating than the preceding months. Interestingly, as the year progresses into the fall, Cincinnati typically witnesses an increase in wind speeds, with November and December averaging 3.1 m/s (7 mph) and 3.3 m/s (7 mph), setting a foundation for a crisp, refreshing winter ahead.

Average September Wind Speed in Cincinnati

The chart displays monthly wind speed patterns in Cincinnati, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.03.33.53.32.72.72.32.12.9 m/s2.93.13.3
Data source: Cincinnati September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Cincinnati Compares to Other Months

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

September and January showcase a striking contrast in weather. September experiences milder temperatures with a minimum of 7°C (44°F) and an average high of 21°C (71°F), allowing for pleasant days and relatively low humidity at 73%. However, it does see some precipitation, averaging 81 mm over 8 days. In stark contrast, January plunges into frigid conditions, with temperatures dropping to a minimum of -24°C (-11°F) and a chilly average of around 1°C (33°F). This month also has similar levels of precipitation at 80 mm, but over 10 days, and a higher humidity of 88%, which can intensify the cold sensation. For more details on January weather, you can refer to Cincinnati weather in January.

September and February present stark contrasts in weather conditions. In September, temperatures range from a mild 7°C (44°F) at night to a high of 35°C (95°F) during the day, with an average of 21°C (71°F). The month sees about 81 mm (3.2 in) of rainfall over approximately 8 days, accompanied by a relative humidity of 73%. In contrast, February features a much colder climate, with nighttime lows plunging to -19°C (-3°F) and daytime highs reaching 26°C (78°F), averaging around 3°C (37°F). This chillier month experiences higher precipitation levels at 107 mm (4.2 in) spread over about 13 days, along with increased humidity at 88%. For a more detailed look at the February climate, check out Cincinnati weather in February.

September and March present contrasting weather patterns. September boasts warmer temperatures, with an average of 21°C (71°F) and a maximum reaching up to 35°C (95°F), compared to March's much cooler average of 7°C (45°F) and a maximum of 26°C (80°F). Additionally, September experiences lesser precipitation, with 81 mm (3.2 in) over 8 days, in contrast to March's higher rainfall of 137 mm (5.4 in) across 13 days. Humidity levels also differ, as September has a humidity of 73%, while March has a slightly higher humidity at 87%. For more detailed insights into March weather, you can visit Cincinnati weather in March.

September and April present contrasting weather patterns. September boasts warmer temperatures, with averages around 21°C (71°F) and highs peaking at 35°C (95°F), making it a generally hotter month despite some rainfall totaling 81 mm (3.2 in) over about 8 days. In contrast, April experiences cooler conditions, with an average of 12°C (55°F) and lows dipping to -3°C (27°F). April also brings more rain, accumulating 119 mm (4.7 in) over approximately 12 days, along with higher humidity levels at 85%. For a detailed look at the weather specifics, check out Cincinnati weather in April.

When comparing the weather in September and May, we see distinct differences in temperature, precipitation, and humidity levels. September typically features milder temperatures, with a minimum of 7°C (44°F) and an average of 21°C (71°F), while May experiences cooler nights, with a minimum of 0°C (33°F) and an average temperature of 19°C (66°F). However, May tends to be wetter, receiving 127 mm (5.0 inches) of rainfall over about 14 days, compared to September's 81 mm (3.2 inches) over 8 days. Additionally, both months have similar humidity levels, with September at 73% and May slightly higher at 81%. For a deeper insight into May’s weather conditions, you can check out Cincinnati weather in May.

In comparing the weather between September and June, we see notable differences in temperature and precipitation patterns. September experiences a broader range of temperatures, with minimums dropping to 7°C (44°F) and maximums reaching up to 35°C (95°F), while the average temperature settles at 21°C (71°F). In contrast, June has slightly higher averages, with minimum temperatures around 9°C (49°F) and maximums peaking at 34°C (94°F), yielding an average of 23°C (74°F). Rainfall also varies, as September receives 81 mm (3.2 in) over about 8 days, whereas June is wetter with 131 mm (5.2 in) across 13 days. Additionally, humidity is slightly lower in September at 73% compared to June, which sees a humidity level of 82%. For more detailed insights, you can check Cincinnati weather in June.

In comparing the weather conditions of September and July, we see notable differences. September experiences a broader temperature range with a minimum of 7°C (44°F) and an average of 21°C (71°F), while July maintains a milder minimum of 15°C (60°F) and a slightly higher average of 25°C (78°F). Both months share the same maximum temperature of 35°C (95°F); however, September tends to be less humid with an average humidity of 73% compared to July's 81%. Rainfall is also higher in July, with 110 mm (4.3 in) over 11 days, while September sees 81 mm (3.2 in) over just 8 days. For more detailed information, you can check Cincinnati weather in July.

In comparing the weather between September and August, September experiences a broader temperature range, with minimums dropping to 7°C (44°F) while maintaining an average of 21°C (71°F) and heating up to a maximum of 35°C (95°F). In contrast, August maintains a milder minimum temperature of 13°C (56°F) and a slightly higher average of 24°C (75°F), peaking at 34°C (93°F). When it comes to precipitation, September sees 81 mm (3.2 in) over 8 days, while August has a tad more rainfall at 89 mm (3.5 in) but over a longer span of 12 days. Both months maintain the same humidity level of 73%. For more detailed insights, check Cincinnati weather in August.

September and October present a noticeable shift in weather patterns. In September, temperatures range from a minimum of 7°C (44°F) to a maximum of 35°C (95°F), with an average of 21°C (71°F). The month experiences 81 mm (3.2 in) of precipitation over 8 days, alongside a humidity level of 73%. In contrast, October sees significantly cooler temperatures, with a minimum of 1°C (34°F), an average of 15°C (59°F), and a maximum of 34°C (94°F). Precipitation increases slightly to 96 mm (3.8 in) over 12 days, accompanied by a higher humidity of 78%. For more detailed insights about October weather, you can check Cincinnati weather in October.

In September, temperatures range from a mild 7°C (44°F) at night to a warm 35°C (95°F) during the day, making it a pleasant month with an average temperature of 21°C (71°F). The month typically sees about 81 mm (3.2 in) of precipitation over 8 days, with humidity around 73%. In stark contrast, November experiences a significant drop in temperature, with minimums plunging to -13°C (9°F) and average temperatures settling at just 7°C (44°F). Although the maximum temperature reaches 26°C (80°F), the month also has higher precipitation levels of 99 mm (3.9 in) over the same number of days, accompanied by increased humidity at 89%. For more detailed information, you can check Cincinnati weather in November.

September and December showcase striking contrasts in weather patterns. September enjoys a warm average temperature of 21°C (71°F), with highs reaching up to 35°C (95°F), while December sees a significant drop, averaging just 4°C (39°F) and peaking at 19°C (67°F). Precipitation also varies, with September receiving 81 mm (3.2 in) over 8 days, compared to December's 110 mm (4.3 in) across 10 days. Additionally, humidity levels rise in December to 87%, surpassing September's 73%, giving the latter month a much drier feel. For more details on December's weather, visit Cincinnati weather in December.

Compare Cincinnati's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Cincinnati

As summer transitions into autumn, September in Cincinnati brings a refreshing shift in weather, contrasting sharply with the sweltering heat of July and August. Average temperatures hover around a pleasant 21°C (71°F), making outdoor activities enjoyable, yet occasional peaks can soar to a maximum of 35°C (95°F). This month also experiences a notable increase in humidity, averaging 73%, while light rains contribute to a total precipitation of 81 mm (3.2 in) across about eight days, offering a subtle nod to the changing seasons. As the days grow shorter and cooler, the weather not only invites a cozy atmosphere but also underscores the beauty of Cincinnati's diverse climate. For a deeper understanding of the city's weather patterns throughout the year, visit Cincinnati Climate.