Last updated: February 24, 2025
In September, the weather in Dennis, United States offers a delightful transition from summer warmth to early autumn chill. With maximum temperatures reaching 25°C (78°F) and an average of 19°C (67°F), the days are pleasantly warm, making it an ideal time for outdoor activities. However, night temperatures can dip to a minimum of 13°C (56°F), reminding residents and visitors of the changing season. This month also experiences notable precipitation, totaling 118 mm (4.7 in) over approximately 10 days, contributing to the region's lush greenery. Coupled with a high humidity level of 75%, the atmosphere remains rich and vibrant, creating a uniquely refreshing climate that characterizes September in Dennis.
As September rolls into Dennis, the warmth of summer begins to gracefully yield to the crisp embrace of autumn. Temperatures typically range from a minimum of 13°C (56°F) to a maximum of 25°C (78°F), creating a pleasantly mild atmosphere perfect for outdoor activities. With an average temperature of 19°C (67°F), the month reflects a comfortable transition, where the lingering warmth of late summer still mingles with the cooler breezes that herald the coming fall. This trend marks a notable rise in temperatures from the early months of the year, illustrating how quickly the landscape can shift from the depths of winter, where lows plunge to -14°C (6°F) in January, to the inviting warmth characteristic of September. The gradual decline in temperatures as the month progresses signals a gentle reminder of the seasonal changes that await.
September in Dennis, United States, showcases a return to moderate rainfall, with precipitation totaling 118 mm (4.7 in) over 10 days. This amount mirrors the precipitation levels of March, indicating a consistent trend of early fall moisture that prepares the region for the wetter months ahead. As summer transitions into autumn, precipitation tends to increase, hinting at nature's shift. This month’s rainfall is slightly higher than the drier summer months, like July and August, both of which received less than 100 mm combined. With October typically experiencing even more rainfall, this September serves as a precursor to the more significant deluges on the horizon, emphasizing the climatic rhythm that defines the seasons in Dennis.
In Dennis, United States, September marks a subtle transition in humidity levels, dropping to 75%. This trend reflects a gradual decline from the heavier humidity of the summer months, with July and August both recorded at 76%. As autumn approaches, the consistent decrease from the spring's 79% in April to September's levels indicates a shift towards drier air. Interestingly, September's humidity mirrors the coming month's October, both maintaining a comfortable 75%. This slight reduction heralds the onset of cooler temperatures and more pleasant weather conditions, offering a refreshing reprieve from the summer's mugginess.
In September, the UV Index in Dennis, United States, remains notably high, with a reading of 8, indicating a very high exposure category and a burn time of just 15 minutes. This month typically showcases a gradual tapering off from the peak summer UV levels, yet caution is still essential for outdoor activities. Following a trend set from the previous months, September continues to demand protective measures against UV radiation, aligning closely with August's UV Index of 9. As the sun begins to shift towards autumn, it's crucial to stay informed about the day's UV levels to ensure safe enjoyment of the lingering warmth. For more detailed insights and updates, visit Dennis UV Index.
UV Risk Categories
September in Dennis, United States, offers a delightful 280 hours of sunshine, marking a gentle transition from the sun-drenched summer months of July and August, which boast an impressive 346 and 330 hours respectively. As the year progresses, sunshine hours gradually decline, with September still holding onto a significant amount of light. This trend continues into the fall, dropping to 236 hours in October. Overall, September serves as a bridge between the vitality of summer and the more subdued light of autumn, allowing residents and visitors alike to bask in the lingering warmth of the season.
In September, Dennis, United States, enjoys a noteworthy 49% chance of sunny weather, marking it as one of the more promising months for those seeking sunshine. This increase is particularly refreshing after the generally lower percentages experienced during the summer months, where the likelihood hovers around the mid-30s. As the year progresses, September stands out with its favorable outlook, especially when compared to the earlier months like February, which sees a mere 28% chance of sun. As temperatures begin to cool, this heightened chance for clear skies provides a delightful opportunity to savor the beautiful early autumn days before the chill of winter settles in.
As September arrives in Dennis, United States, the daylight duration begins its subtle descent, offering around 12 hours of light each day. This slight decrease marks a transition from the peak brightness of the summer months, where June held 15 hours of daylight, gradually giving way to the cozy ambiance of autumn. Following a 14-hour stretch in July and a moderate 13 hours in August, September signals the shift toward shorter days, resembling the patterns seen in October and November, where daylight dwindles to 11 and 9 hours respectively. Overall, the trend showcases a rhythmic ebb and flow of daylight, inviting residents to savor the changing seasons and the beautiful hues that autumn brings.
As September rolls into Dennis, United States, the average wind speed picks up slightly to 5.9 m/s (13 mph), mirroring the gentle breezes of May. After the summer months, when winds languished at their lowest, September introduces a welcome transition into the fall. This modest increase indicates a shift from the warm, calm days of summer towards a crisper, livelier autumn atmosphere. In comparison to the preceding months, September's winds are notably more vigorous than the lethargic gusts of August, hinting at nature’s gradual preparation for the stronger winds that October and November will bring, which typically average between 6.6 m/s (15 mph) and 6.7 m/s (15 mph). Thus, September stands as a bridge, gently guiding residents and visitors alike from the leisurely pace of summer towards the invigorating spirit of fall.
The weather in Dennis 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 Dennis and find detailed weather information for every month.
In September, temperatures are notably milder, ranging from a minimum of 13°C (56°F) to a maximum of 25°C (78°F), with an average of 19°C (67°F). The month sees considerable precipitation, totaling 118 mm (4.7 in) over about 10 days, accompanied by a relative humidity of 75%. In contrast, January presents a starkly different climate, with much colder temperatures that can plunge to a minimum of -14°C (6°F) and only reach a maximum of 13°C (55°F), averaging just 2°C (36°F). While January experiences slightly less precipitation at 94 mm (3.7 in) over the same number of days, it boasts higher humidity levels at 84%. For more details on January weather, check out Dennis weather in January.
In comparing the weather of September and February, we see a stark contrast in temperatures and conditions. September boasts milder temperatures, ranging from a minimum of 13°C (56°F) to a maximum of 25°C (78°F), with an average of 19°C (67°F). It experiences 118 mm (4.7 in) of precipitation over about 10 days, with humidity levels around 75%. In contrast, February is much colder, with temperatures dipping as low as -12°C (10°F) and only reaching a maximum of 11°C (53°F), averaging at just 2°C (36°F). This month sees slightly higher precipitation at 123 mm (4.8 in) over 12 days, and humidity levels rise to 84%. For more detailed information about weather in February, you can visit Dennis weather in February.
September typically ushers in mild temperatures, ranging from a minimum of 13°C (56°F) to a comfortable maximum of 25°C (78°F), with an average of 19°C (67°F). In contrast, March is significantly cooler, featuring temperatures that can drop to a minimum of -9°C (16°F) and peak at a maximum of 13°C (56°F), averaging just 3°C (38°F). Both months see an equal amount of precipitation, averaging 118 mm (4.7 in) over about 10 days, but September has a lower humidity level at 75% compared to March's higher humidity of 82%. For a detailed look at the March weather in Dennis, you can check out Dennis weather in March.
In comparing the weather between September and April, we see notable differences in temperature and precipitation. September enjoys milder temperatures, with a minimum of 13°C (56°F) and an average of 19°C (67°F), while April is considerably cooler, featuring a minimum of 1°C (33°F) and an average of just 7°C (46°F). Rainfall also varies, with September averaging 118 mm (4.7 in) over about 10 days, compared to April's slightly higher 137 mm (5.4 in) spread across 13 days. Additionally, humidity levels are slightly higher in April at 79%, compared to September's 75%. For more detailed insights into April weather, you can explore Dennis weather in April.
September and May exhibit distinct weather patterns. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 25°C (78°F), with an average of 19°C (67°F). This month also sees about 118 mm (4.7 in) of precipitation over approximately 10 days, accompanied by a humidity level of 75%. Conversely, May is cooler, with temperatures spanning from a minimum of 5°C (41°F) to a maximum of 21°C (70°F), and an average of 12°C (53°F). Despite having slightly more precipitation at 119 mm (4.7 in) over 12 days, May shares the same humidity level of 75%. For more details, you can check Dennis weather in May.
When comparing the weather in September to that of June, we observe that September typically has slightly warmer temperatures, with an average of 19°C (67°F) compared to June's average of 17°C (63°F). September also boasts higher maximum temperatures, reaching up to 25°C (78°F), while June peaks at 24°C (76°F). However, September experiences greater precipitation, totaling 118 mm (4.7 in) over 10 days, compared to June's 91 mm (3.6 in) under the same number of rainy days. Despite the increased rainfall in September, the humidity levels remain similar, with September at 75% and June slightly higher at 78%. For more details on the weather in June, visit Dennis weather in June.
When comparing the weather in September to that of July, we observe notable differences in both temperature and precipitation. September features a more moderate temperature range, with minimums of 13°C (56°F) and maximums reaching 25°C (78°F), while July tends to be warmer, boasting minimums of 16°C (61°F) and maximums of 29°C (84°F). In terms of precipitation, September experiences more rainfall, averaging 118 mm (4.7 in) over about 10 days, compared to July's 83 mm (3.3 in) over 9 days. Humidity levels remain quite similar, with September at 75% and July slightly higher at 76%. For a closer look at the specific weather conditions during July, you can explore Dennis weather in July.
When comparing the weather in September to August, it becomes evident that September is slightly cooler overall. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 25°C (78°F), with an average temperature of 19°C (67°F). In contrast, August experiences warmer conditions, with a minimum of 16°C (61°F), an average of 22°C (72°F), and a maximum of 27°C (81°F). Additionally, September sees more precipitation, totaling 118 mm (4.7 in) over 10 days, compared to August's 82 mm (3.2 in) over 8 days. Humidity levels remain similar, with September at 75% and August at 76%. For more details on August weather, you can visit Dennis weather in August.
In comparing the weather between September and October, we can observe quite a shift in temperature and precipitation patterns. September typically features milder temperatures, with an average of 19°C (67°F), while October sees a noticeable drop, averaging just 15°C (59°F). The maximum temperatures also decline, going from 25°C (78°F) in September to 22°C (72°F) in October. Rainfall increases in October, with total precipitation rising to 175 mm (6.9 in) over 12 days compared to September’s 118 mm (4.7 in) over 10 days. Despite the increase in rain, the humidity remains constant at 75% for both months. For more detailed insights into the weather, you can check Dennis weather in October.
September and November present a marked contrast in weather conditions. September enjoys milder temperatures, with a minimum of 13°C (56°F) and an average around 19°C (67°F), peaking at 25°C (78°F). In contrast, November brings a chillier climate, where temperatures can drop to a minimum of -6°C (21°F), with an average of 9°C (48°F) and a maximum of 19°C (66°F). Although both months experience around 10 days of precipitation, September sees a higher total rainfall of 118 mm (4.7 in) compared to November’s 102 mm (4.0 in). Additionally, humidity rises slightly in November to 80%, compared to September’s 75%. For more specific weather details, you can check Dennis weather in November.
In September, the weather is generally mild, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 25°C (78°F) and an average of 19°C (67°F). The month experiences a fair amount of rainfall, totaling 118 mm (4.7 in) over approximately 10 days, with humidity levels around 75%. In contrast, December brings a significant drop in temperatures, featuring a minimum of -12°C (11°F) and an average of just 4°C (40°F), while reaching a maximum of 15°C (60°F). This colder month also sees slightly higher precipitation at 136 mm (5.4 in) over 12 days and an increase in humidity to 80%. For more detailed weather information during this time, check out Dennis weather in December.
As summer transitions to autumn, September in Dennis presents a delightful shift in weather. With average temperatures cooling to a comfortable 19°C (67°F) and maximums lingering around 25°C (78°F), the days are still warm but offer a welcome break from the summer heat. Rainfall becomes more frequent, with about 10 days of precipitation and an overall accumulation of 118 mm (4.7 in), highlighting a shift towards a more humid climate at 75%. This blend of warmth and moisture sets a picturesque backdrop for fall activities in the area. For more detailed information, check out Dennis Climate.