Last updated: February 24, 2025
September in Bristol, United States offers a tantalizing blend of warm days and cool nights, with maximum temperatures soaring to 33°C (91°F) while the average settles at a comfortable 19°C (67°F). However, early autumn also brings its share of moisture, with a total precipitation of 97 mm (3.8 in) across 9 days, contributing to a humidity level of 75%. This combination of warm temperatures and increased humidity makes September a transitional month, where the vibrant colors of fall begin to emerge amid the lingering warmth of summer.
In September, Bristol, United States, experiences a delightful transition into autumn, with temperatures reflecting a comfortable balance. The minimum temperature hovers around 6°C (43°F), while the average reaches a pleasant 19°C (67°F), and the maximum can climb to 33°C (91°F), making it one of the last warm months of the year. This month marks a drop from the intense heat of summer, as temperatures gradually shift downward from the peaks seen in July and August. The consistent warmth in September allows for ample outdoor activities before the chill of autumn sets in, showcasing nature's vibrant colors and creating a perfect backdrop for seasonal festivities.
In September, Bristol experiences a moderate level of precipitation, receiving 97 mm (3.8 in) of rain over approximately 9 days. This month showcases a slight decline compared to the heavier downpours noted in the summer months, such as July and August, which recorded 122 mm (4.8 in) and 92 mm (3.6 in), respectively. September's rainfall is consistent with the late summer transition into autumn, marking a shift towards the wetter fall season. As the year progresses, precipitation amounts begin to rise again, peaking in October with 135 mm (5.3 in), indicating that September serves as a bridge between the warm rain patterns of summer and the more intense autumn rains.
As summer transitions into autumn, September in Bristol, United States, exhibits a moderate humidity level of 75%. This marks a slight decrease from the peak of 76% experienced in the late summer months of July and August. Throughout the year, Bristol's humidity shows a notable trend: it remains quite high during the winter months, hovering around 84% in January and February, before gradually tapering off to its lowest in late spring. The drop in humidity from August to September suggests a welcoming refresh as the crisp fall air begins to set in, creating an inviting environment for both residents and visitors alike.
In September, the UV Index in Bristol, United States, reaches a significant 8, maintaining its status as a very high exposure category. Just as summer begins to transition into fall, outdoor enthusiasts must remain vigilant, with a burn time of only 15 minutes for unprotected skin. This trend suggests a gradual decline from the peak UV levels experienced in June and July, yet the risk remains elevated. Awareness of these changing conditions is crucial, as the mild warmth of early autumn may lure many outdoors. For more detailed information on UV levels throughout the year, visit Bristol UV Index.
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September in Bristol is a delightful transition into autumn, with 282 hours of sunshine illuminating the month. Following the radiant peak of summer, where July boasts the highest sunshine at 347 hours, September still enjoys a generous amount of daylight, although slightly less than the vibrant August, which offers 329 hours. As the days begin to shorten, the warm glow of September reflects the gradual shift towards cooler weather, yet it remains a notable month for basking in the sun compared to the winter months ahead. The trend of increasing sunshine from January’s 150 hours to the summer's peak underscores Bristol's appeal as a sunny getaway, making September a perfect time to revel in the lingering warmth before autumn settles in.
When it comes to sunny weather in Bristol, United States, September stands out with a 44% chance of sunshine, making it one of the more favorable months for enjoying clear skies before autumn arrives. This percentage indicates a slight recovery compared to the previous summer months, as both July and August dip to 36% and 30% respectively. Moreover, September's sunny potential is higher than several spring and early summer months, such as April (43%) and June (38%). While not the sunniest month of the year, September offers an appealing blend of pleasant temperatures and increased likelihood of sun, ushering in the season change with a hint of brightness. As we look ahead, the chances begin to creep up again in November, reaching 55%, suggesting that sunny days are not completely behind us just yet.
As summer wanes, September in Bristol, United States, ushers in a gentle transition with approximately 12 hours of daylight. This marks a gradual decline from the sun-drenched days of July and August, which boast 14 and 13 hours of daylight, respectively. The month offers a balanced mix of light and shadow, setting the stage for the vibrant colors of autumn that follow. Following September, daylight hours continue to dwindle, dipping to 11 hours in October and settling at 9 hours by November. This shifting pattern highlights the rhythm of the seasons, inviting residents to savor the lingering warmth and beauty before the shorter days of winter arrive.
In September, Bristol experiences a gentle revival in wind activity, with an average speed of 3.4 m/s (8 mph) that slightly picks up from the lull of the summer months. Following a steady decline throughout July and August, where winds diminished to their lowest, September brings a refreshing change as breezes begin to stir once more. This month’s wind speeds mirror those of late spring, hinting at a transitional shift as the region prepares for the crispness of autumn. Overall, the trend suggests a consistent pattern as Bristol winds remain relatively stable, with only minor fluctuations, keeping the air vibrant and inviting.
The weather in Bristol 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 Bristol and find detailed weather information for every month.
September and January present contrasting weather patterns. In September, temperatures range from a minimum of 6°C (43°F) to a maximum of 33°C (91°F), with an average of 19°C (67°F). The month experiences significant rainfall, totaling 97 mm (3.8 in) over 9 days, and humidity averages around 75%. In stark contrast, January features much colder temperatures, with a minimum of -20°C (-4°F), an average of 0°C (33°F), and a maximum of 20°C (69°F). Precipitation in January is slightly lower at 74 mm (2.9 in) and occurs over 8 days, accompanied by higher humidity levels of 84%. For more detailed insights, you can check this link: Bristol weather in January.
September and February present stark contrasts in weather. In September, temperatures can reach a maximum of 33°C (91°F) with an average of 19°C (67°F), while the nights cool down to a minimum of 6°C (43°F). The month sees about 97 mm (3.8 in) of precipitation spread across 9 days, with a humidity level around 75%. Conversely, February is characterized by much colder temperatures, where the maximum only hits 19°C (67°F), but the average temperature drops to 1°C (35°F) and can plummet to a chilling minimum of -16°C (3°F). Although it doesn't rain as much, with about 92 mm (3.6 in) of precipitation over 11 days, the humidity remains higher at 84%. For a closer look at February weather conditions, you can visit Bristol weather in February.
In comparing the weather of September and March, a stark contrast emerges in temperature and conditions. September enjoys milder temperatures, with a minimum of 6°C (43°F) and an average of 19°C (67°F), peaking at 33°C (91°F). In contrast, March is significantly colder, with temperatures dropping to a minimum of -14°C (7°F) and an average of only 4°C (39°F). While both months experience a fair amount of precipitation, September's 97 mm (3.8 in) over 9 days slightly contrasts with March's 102 mm (4.0 in) over 10 days. Additionally, March is marked by higher humidity at 82%, compared to September's 75%. For more detailed insights into March weather, you can check Bristol weather in March.
When comparing the weather in September and April, notable differences emerge. September typically enjoys warmer temperatures, with a minimum of 6°C (43°F) and an average of 19°C (67°F), reaching highs of 33°C (91°F). In contrast, April experiences cooler conditions, starting with a minimum of -3°C (27°F) and averaging at 9°C (49°F), with a maximum of 28°C (82°F). Precipitation is more frequent in April, with 123 mm (4.9 in) over 12 days, compared to September's 97 mm (3.8 in) across 9 days. Humidity levels are slightly higher in April at 79%, while September's humidity is recorded at 75%. This link provides more details: Bristol weather in April.
September and May both offer warm temperatures, with maximums reaching up to 33°C (91°F), but their overall climates differ. September's average temperature is warmer at 19°C (67°F) compared to May's 15°C (58°F), which often results in a more comfortable feel during late summer. However, May has slightly higher precipitation, averaging 101 mm (4.0 in) over 12 days, as opposed to September's 97 mm (3.8 in) over 9 days. Both months experience a humidity level of 75%, contributing to the overall muggy atmosphere common in transitional seasons. For more specifics on May weather, check out Bristol weather in May.
September and June weather exhibit some similarities, yet notable differences. Both months experience a range of temperatures, with September having a minimum of 6°C and a maximum of 33°C, while June starts slightly warmer with a minimum of 8°C and a maximum of 34°C. Humidity is relatively high in both months, with September at 75% and June slightly higher at 78%. Additionally, precipitation levels are the same at 97 mm, but June sees rain on 11 days compared to September's 9 days. For a closer look at June weather, check out Bristol weather in June.
When comparing the weather in September and July, notable differences emerge in temperature and precipitation. September experiences a broader temperature range, with minimums dropping to 6°C (43°F) and maximums reaching up to 33°C (91°F), while the average temperature is 19°C (67°F). In contrast, July is typically warmer, with minimum temperatures around 13°C (56°F) and maximums climbing to 37°C (99°F), resulting in an average of 23°C (74°F). Both months see considerable precipitation, but July receives slightly more at 122 mm (4.8 in) over 12 days compared to September's 97 mm (3.8 in) over 9 days. Humidity levels remain similar, with September at 75% and July slightly higher at 76%. For a more detailed look, you can check out Bristol weather in July.
In comparing the weather between August and September, we can observe some notable differences. August generally experiences warmer temperatures, with a minimum of 11°C (52°F) and an average of 23°C (74°F), peaking at 34°C (94°F). In contrast, September starts to cool down, featuring a lower minimum temperature of 6°C (43°F) and an average of 19°C (67°F), with a maximum reaching 33°C (91°F). Precipitation levels are slightly higher in September, with 97 mm (3.8 in) falling over 9 days compared to August’s 92 mm (3.6 in) across 11 days. Humidity remains similarly high, with September at 75% and August at 76%. For a more detailed look at the weather specifics, check out Bristol weather in August.
In comparing the weather between September and October, September typically experiences milder temperatures, ranging from a minimum of 6°C (43°F) to a maximum of 33°C (91°F), with an average temperature of 19°C (67°F). It has relatively lower precipitation at 97 mm (3.8 in) over 9 days. In contrast, October sees a notable drop in temperatures, with a minimum of -1°C (31°F) and an average of 14°C (57°F), while the maximum reaches 27°C (81°F). Rainfall increases in October, amounting to 135 mm (5.3 in) over 11 days. Despite the rise in precipitation, humidity remains steady at 75%. For more detailed information, you can visit Bristol weather in October.
September and November present striking contrasts in weather. September boasts a wide range of temperatures, with a minimum of 6°C (43°F) and a maximum of 33°C (91°F), making it generally warmer with an average of 19°C (67°F). In contrast, November sees a significant drop, featuring a minimum of -10°C (14°F) and an average temperature of only 7°C (45°F). Precipitation levels are relatively similar, with September receiving 97 mm (3.8 in) of rain and November slightly higher at 101 mm (4.0 in), both accumulating over nine days. Additionally, November's humidity increases to 80%, slightly higher than September's 75%. For more details on November conditions, visit Bristol weather in November.
September and December present dramatically different weather conditions. In September, temperatures range from a mild 6°C (43°F) to a warm 33°C (91°F), with an average of 19°C (67°F). The month sees about 97 mm (3.8 in) of rainfall over 9 days, accompanied by a relative humidity of 75%. In contrast, December experiences much colder weather, with temperatures plummeting to a minimum of -15°C (5°F) and an average of only 2°C (36°F), peaking at 17°C (63°F). December is slightly wetter, with precipitation reaching 120 mm (4.7 in) over 10 days and humidity increasing to 80%. For a more detailed look at December weather, visit Bristol weather in December.
As summer transitions to autumn, September in Bristol showcases a delightful mix of warmth and coolness. The pleasant average temperatures invite outdoor activities, while occasional rainfall adds a refreshing touch to the scenery. With humidity levels at a comfortable 75%, the month strikes a balance that differs notably from the harsher extremes of both summer's heat and winter's chill. This transitional period is perfect for experiencing the vibrant fall colors without the intense weather fluctuations of earlier months. For a deeper dive into Bristol's weather patterns, check out Bristol Climate.