Last updated: February 24, 2025
September in Louisville, United States, offers a dynamic weather experience characterized by warm temperatures and moderate humidity. Max temperatures reach up to 36°C (97°F), while the average hovers around 22°C (72°F), providing an inviting climate for outdoor activities. As the month progresses, cooler nights bring lows of 8°C (47°F), creating a refreshing contrast. Rainfall is a notable feature, with 112 mm (4.4 in) of precipitation spread over 8 days, adding a lushness to the surrounding landscape. With an average humidity of 69%, September balances warmth and moisture, making it a vibrant month for both residents and visitors.
September in Louisville ushers in a delightful transition into fall, characterized by mild temperatures and warm days. With nighttime lows averaging around 8°C (47°F), the air begins to cool from the summer heat. Daytime highs can soar to a sizzling 36°C (97°F), maintaining the summer's warmth before cooler autumn breezes take hold. The average temperature of 22°C (72°F) reflects a mellowing of the season, inviting outdoor activities and festivals amidst the vibrant fall foliage. As the month progresses, the promise of crisp, refreshing air emerges, making September a remarkable time to enjoy the dynamic weather shifts in this charming Southern city.
September in Louisville sees a notable shift in precipitation patterns, receiving an average of 112 mm (4.4 in) of rain over 8 days. This marks a slight increase compared to the summer months, where July and August recorded 98 mm and 94 mm, respectively. As the city transitions into fall, the drop in precipitation days indicates a more stable weather pattern, allowing for longer stretches of clearer skies. This trend of moderate rainfall showcases September as a month where the tail end of summer meets the welcoming embrace of autumn, striking a balance that keeps the landscape lush while preparing for the drier, cooler days ahead.
September in Louisville marks a notable shift in humidity levels, dipping to 69%, the lowest point since the onset of warmer months. After the heavier humidity of summer—with highs of 79% in July and 70% in August—this decline signals a transition into fall. As the air begins to dry out, it reflects the city's seasonal rhythm, where the humidity bounces back to 76% by October. This month serves as a reminder of Louisville's humid climate, particularly in contrast to the much higher figures found in the winter months, like 87% in January and 88% in November. Overall, September's more comfortable moisture levels create a refreshing prelude to the crisp air ahead.
As summer transitions into fall, September in Louisville, United States, sees a UV Index of 8, categorizing it as very high. This marks a slight decline from the peak summer months, yet caution remains essential, with a burn time of just 15 minutes for unprotected skin. The trend throughout the year reflects an escalation in UV exposure, climbing from a moderate level of 3 in January to an extreme 11 in June, before tapering off as autumn approaches. Nevertheless, the potential for harmful UV radiation persists, reminding residents to stay vigilant and protect their skin while enjoying the outdoors. For more detailed information on UV exposure throughout the year, visit Louisville UV Index.
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As summer fades into autumn, September in Louisville showcases a splendid balance of sunshine with 281 hours of sunlight, reflecting the remnants of warmer days yet heralding the cooler months ahead. This month experiences a gentle decline from July’s peak of 345 hours, but it still holds onto a generous amount compared to the earlier months of the year. After a steady rise through spring, with April and May enjoying 241 and 287 hours respectively, September’s light offers a warm embrace for outdoor activities before the fall chill sets in. With daylight gradually diminishing as October approaches, this month serves as a perfect transition for residents who relish both sunshine and the vibrant colors of autumn.
September in Louisville, United States, ushers in a wonderful 57% chance of sunny weather, making it one of the brightest months of the year. This marks a noticeable increase compared to the earlier summer months, where the chances hover between 38% to 47%. After a transitional spring that sees sun levels rising, September's sun-soaked days stand out, offering a perfect backdrop for outdoor activities. The warmer, sunnier climate continues into fall, with the likelihood of clear skies creating a delightful blend of pleasant temperatures and abundant sunshine that residents and visitors alike can enjoy.
As summer wanes in September, Louisville experiences a subtle shift in daylight, with the duration tapering to 12 hours of sunlight. This marks a gentle transition from the longest days of June and July, where daylight peaks at 14 hours, to the shorter hours of fall and winter ahead. While September still offers ample sunlight for outdoor activities, the decreasing trend mirrors the approach of autumn, emphasizing the cyclical nature of seasons. With each passing month, daylight gradually recedes, showcasing the beauty of change in Louisville's sky.
As September arrives in Louisville, the winds begin to whisper a gentle transition from the sultry summer months to the more refreshing embrace of autumn. With an average wind speed of 2.4 m/s (5 mph), September’s breezes mark a slight uptick from the lull of August, yet remain among the milder winds of the year. This gradual increase hints at the shifting seasons, as the city starts to prepare for the more invigorating gusts of October and November, which see averages rise back to 2.7 m/s (6 mph) and 2.8 m/s (6 mph) respectively. The trend of diminishing wind speed in the hot summer months gives way to a gentle reawakening in fall, creating a perfect canvas for the vibrant colors and cooler temperatures that come with the changing leaves.
The weather in Louisville 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 Louisville and find detailed weather information for every month.
In September, the weather exhibits a warm range, with minimum temperatures around 8°C (47°F), average highs of 22°C (72°F), and the potential to reach up to 36°C (97°F). This month sees a moderate amount of precipitation at 112 mm (4.4 in) over approximately 8 days, with a relative humidity of 69%. In stark contrast, January presents a much colder climate, with temperatures ranging from a chilling -18°C (0°F) to a milder 20°C (68°F), averaging around 2°C (35°F). Despite having slightly lower precipitation at 87 mm (3.4 in) over about 9 days, January's humidity is higher at 87%. For a more detailed look at the winter climate, check out Louisville weather in January.
September and February present starkly contrasting weather patterns. In September, temperatures range from a mild 8°C (47°F) at night to a sweltering 36°C (97°F) during the day, averaging around 22°C (72°F). The month sees an average of 112 mm (4.4 in) of precipitation over approximately 8 days, with humidity levels at 69%. In contrast, February experiences much chillier conditions, with nighttime lows plunging to -18°C (0°F) and daytime highs reaching a comfortable 26°C (79°F), resulting in an average of just 4°C (40°F). The precipitation in February totals 128 mm (5.0 in) over about 13 days, and the humidity is notably higher at 85%. For more details about February weather, you can check out Louisville weather in February.
When comparing September and March weather, significant differences are evident. September typically enjoys warmer temperatures, ranging from a minimum of 8°C (47°F) to a maximum of 36°C (97°F), with an average of 22°C (72°F). In contrast, March experiences much cooler temperatures, with lows plunging to -12°C (11°F) and highs reaching 27°C (81°F), averaging around 9°C (48°F). Precipitation is also a factor, with September receiving 112 mm (4.4 in) over 8 days, while March sees slightly higher precipitation at 132 mm (5.2 in) over 13 days. Additionally, humidity levels are higher in March at 86%, compared to 69% in September. For further details, you can check Louisville weather in March.
September and April present contrasting weather patterns, each with its unique characteristics. In September, temperatures fluctuate more dramatically, with minimums around 8°C (47°F) and maximums reaching up to 36°C (97°F), resulting in an average of 22°C (72°F). This month experiences a moderate level of rainfall, totaling 112 mm (4.4 in) over about 8 days, accompanied by a humidity level of 69%. In contrast, April is significantly cooler, with minimum temperatures dipping to -3°C (27°F) and maximums reaching 29°C (84°F), averaging at 13°C (56°F). It sees slightly higher precipitation at 137 mm (5.4 in) over 12 days, along with increased humidity at 84%. These differences showcase the transition from summer's warmth in September to the cooler, more variable spring conditions of April. For more details, visit Louisville weather in April.
In September, temperatures range from a cool 8°C (47°F) at night to a warm average of 22°C (72°F), with highs reaching up to 36°C (97°F). This month sees moderate precipitation, averaging 112 mm (4.4 in) across about 8 rainy days, and humidity is recorded at 69%. In contrast, May offers a cooler start with minimum temperatures hitting 0°C (33°F) and average temperatures around 20°C (67°F), peaking at 33°C (92°F). Although May experiences slightly higher precipitation at 128 mm (5.0 in) over 14 days, humidity rises to 79%, contributing to a more humid atmosphere. For a deeper look at May weather specifics, you can check Louisville weather in May.
When comparing the weather in September and June, both months exhibit warm temperatures, but there are notable differences. September typically sees a minimum temperature of 8°C (47°F) and an average of 22°C (72°F), peaking at a warm 36°C (97°F). In contrast, June has a slightly higher average temperature of 24°C (75°F) and a minimum of 9°C (49°F), with a maximum of 34°C (93°F). Regarding precipitation, September receives 112 mm (4.4 in) over about 8 days of rain, while June is wetter, with 151 mm (5.9 in) across 12 rainy days. Humidity levels are also higher in June at 82%, compared to September's 69%. For a more detailed look at June's weather, check out Louisville weather in June.
In September, the weather shows a more significant range in temperatures, with a minimum of 8°C (47°F) and a maximum of 36°C (97°F), leading to an average of 22°C (72°F). In contrast, July is generally warmer, featuring a minimum temperature of 15°C (60°F) and an average of 26°C (79°F), peaking at 35°C (95°F). While September experiences a slightly higher amount of rainfall at 112 mm (4.4 in) over about 8 days, July has a bit less precipitation, totaling 98 mm (3.9 in) over 11 days. The humidity is also notable; September has an average of 69%, while July is more humid at 79%. Overall, September offers a wider temperature variation and increased rainfall, whereas July is consistently warmer and more humid. For a detailed look at July weather, check out Louisville weather in July.
In September, temperatures begin to cool down slightly compared to August, with minimum temperatures dropping from 13°C (56°F) in August to 8°C (47°F) in September. The average temperature also decreases from 25°C (76°F) in August to 22°C (72°F) in September, although the maximum temperature in September can reach up to 36°C (97°F), comparable to August's peak of 35°C (95°F). Precipitation increases in September, totaling 112 mm (4.4 in) over 8 days, while August sees slightly less rain at 94 mm (3.7 in) over 11 days. Humidity remains similar, with September recording 69% and August slightly higher at 70%. For more detailed insights, you can check Louisville weather in August.
September and October showcase a notable shift in weather patterns. In September, temperatures range from a low of 8°C (47°F) to a high of 36°C (97°F), with an average of 22°C (72°F), making it a warm month. Rainfall is significant, totaling 112 mm (4.4 in) over about 8 days, with a humidity level of 69%. In contrast, October brings cooler temperatures, with minimums dropping to -1°C (31°F) and an average of 16°C (60°F), while highs reach 35°C (96°F). Although October experiences slightly less precipitation at 98 mm (3.9 in) over 10 days, humidity increases to 76%. For more details, you can check out Louisville weather in October.
In September, temperatures in Louisville can range from a mild minimum of 8°C (47°F) to a scorching maximum of 36°C (97°F), with an average of 22°C (72°F). The month experiences relatively high humidity at 69% and receives about 112 mm (4.4 in) of precipitation over approximately 8 days.
Contrastingly, November brings a significant drop in temperature, with minimums plummeting to -10°C (14°F) and an average of only 7°C (45°F), while the maximum reaches a more modest 27°C (80°F). Though it sees slightly less precipitation at 88 mm (3.5 in) over about 9 days, the humidity rises considerably to 88%. For more details, check out Louisville weather in November.
September weather is characterized by warm temperatures, with averages around 22°C (72°F) and maximums reaching up to 36°C (97°F), making it a typically summer-like month. In contrast, December brings a significant temperature drop, with average highs of only 5°C (41°F) and nighttime lows plummeting to -14°C (8°F). While both months experience notable precipitation, September has a higher average daily humidity of 69%, compared to December's 87%, which can make the winter month feel even colder. For more detailed insights on winter weather, you can check out Louisville weather in December.
As September unfolds in Louisville, the weather shifts dramatically, offering a warm embrace that often contrasts with the cooler nights. The average temperatures hover around a comfortable 22°C (72°F), yet the month can sizzle, peaking at a scorching 36°C (97°F). Unlike the heavy rains of summer, September features relatively moderate precipitation, with just 8 days experiencing rainfall, contributing to a total of 112 mm (4.4 in). The humidity settles at a manageable 69%, allowing for pleasant outdoor activities as fall approaches. Overall, September serves as a transitional bridge from summer's heat to autumn's cooler embrace, making it a unique month worth exploring. For more insights, check Louisville Climate.