Last updated: February 24, 2025
September in Deer Isle, United States offers a pleasant transition into autumn, with temperatures peaking at a maximum of 22°C (72°F) and averaging around 16°C (60°F). Nights cool down to a refreshing minimum of 9°C (48°F), providing a comfortable climate for outdoor activities. Although the month experiences a total precipitation of 102 mm (4.0 in) over 8 days, the humidity remains relatively high at 77%, creating a unique coastal atmosphere. This blend of mild temperatures and occasional rain makes September an ideal time to explore the natural beauty and charm of Deer Isle.
In September, Deer Isle experiences a transition into the cooler embrace of autumn, bringing comfortable temperatures that range from a minimum of 9°C (48°F) to a maximum of 22°C (72°F). The average temperature settles at a pleasant 16°C (60°F), making it an ideal month for outdoor activities and soaking in the vibrant fall foliage. This marks a significant shift from the warmth of summer, as the temperatures cool down from August's minima of 13°C (57°F) and maxima of 23°C (73°F). As the month progresses, there's a noticeable drop in the warmth characteristic of the peak summer months, signaling the approach of crisper days ahead. Overall, September on Deer Isle embodies a balance of mild warmth and the subtle onset of autumn chill, creating a delightful atmosphere for residents and visitors alike.
In September, Deer Isle experiences a notable shift in precipitation, with 102 mm (4.0 in) of rain falling over 8 days. This amount reflects a slight increase compared to the drier summer months of July and August, suggesting a transition towards the wetter fall season. The September rainfall patterns harmoniously align with the broader trend of increasing precipitation as the year progresses, culminating in the heavier downpours characteristic of fall and winter. As the weather shifts, the island's lush landscapes are rejuvenated, setting the stage for the vibrant autumn hues that envelop Deer Isle in the following months.
In September, Deer Isle experiences a slight uptick in humidity, reaching 77%. This marks a small rise from the consistently lower levels observed during the summer months, where humidity lingered around 74% from June through August. As autumn approaches, the air begins to feel a touch more humid, reminiscent of the higher levels seen in the earlier spring months. Following September, humidity levels will gradually increase again, peaking in November at 85%. The transition from summer to fall in Deer Isle highlights a shift in atmospheric conditions that sets the stage for the cooler, more moisture-laden months ahead.
As September rolls in Deer Isle, the UV Index reflects a notable shift in sun exposure, with a reading of 7 that classifies as high. This marks a slight decrease from the very high levels experienced during the peak summer months of June through August, where the UV Index consistently hovered at 9. With burn times shortening to 25 minutes, it’s a reminder to stay vigilant about sun protection as daylight begins to wane. Compared to the earlier months of the year, where the UV Index started at a mere 2 in January, September still encourages outdoor enthusiasts to embrace the sunshine while taking necessary precautions. For more detailed information on UV levels throughout the year, check out the Deer Isle UV Index.
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As summer transitions into autumn, September in Deer Isle continues to bask in generous sunshine, accumulating an impressive 278 hours of sunlight. This month marks a slight decline from August's peak of 325 hours, yet it still maintains a vibrant glow, significantly outpacing the earlier months of the year. The trend reveals a clear seasonal pattern, where longer days dominate from May through August, offering joyful outdoor experiences before the days shorten further into fall. With the warmth of summer still lingering, September provides a beautiful backdrop, inviting both locals and visitors to savor the last remnants of sunlight before the brisk chill of October sets in.
In Deer Isle, September brings a modest 42% chance of sunny weather, making it one of the more favorable months for sunshine as summer fades into fall. This slight uptick in sunny days contrasts with the notably lower probabilities seen in July and August, where the likelihood drops to 26% and 29%, respectively. Interestingly, as the seasons shift, October follows closely behind September with a 43% chance of sun, suggesting a consistent pattern of improved weather as the crispness of autumn sets in. Overall, September stands out as a more promising month for sun-seekers, providing a delightful opportunity to enjoy the beauty of Deer Isle as nature begins its transformation.
In Deer Isle, United States, the month of September marks a gentle transition in daylight, with an average of 12 hours illuminating the days. This decrease from the summer peak of 15 hours in June and July reflects the gradual shift toward autumn. As the sun begins to set earlier, the island's vibrant landscape transforms, offering a soft palette of fall colors. Following September, daylight continues to dwindle, preparing the community for the cozy embrace of fall and winter, with just 10 hours of sunlight anticipated in October. This rhythmic ebb and flow of daylight plays a vital role in the region's natural beauty and the seasonal activities enjoyed by its residents and visitors.
As summer transitions into autumn, September in Deer Isle, United States, experiences a slight resurgence in wind activity, with an average speed of 5.4 m/s (12 mph). While this marks an increase from the notably calm summer months of July and August, it remains below the brisker early months of the year. Notably, the wind picks up again in October, suggesting that as the days grow shorter and cooler, the gales return. This trend of increasing wind speeds post-summer is reminiscent of the sharper gusts seen from January to March, when the winds reach their peak, consistently hovering above 7 m/s. Overall, September serves as a gentle precursor to the invigorating winds of fall, hinting at nature's transition while maintaining a serene coastal atmosphere.
The weather in Deer Isle 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 Deer Isle and find detailed weather information for every month.
September and January present stark contrasts in weather conditions. In September, temperatures range from a mild 9°C (48°F) at minimum to a pleasant 22°C (72°F) at maximum, with an average of 16°C (60°F). The month experiences around 102 mm (4.0 in) of precipitation over 8 days and a humidity level of 77%. In contrast, January brings much colder temperatures, with a minimum of -17°C (2°F), an average of -2°C (29°F), and a maximum of 10°C (50°F). Precipitation increases to 108 mm (4.3 in) over 9 days, accompanied by higher humidity at 88%. For more detailed information on January weather, you can visit Deer Isle weather in January.
September weather is generally more temperate, with average temperatures ranging from a minimum of 9°C (48°F) to a maximum of 22°C (72°F), and a moderate level of humidity at 77%. In contrast, February experiences much cooler conditions, with average temperatures hovering around -1°C (30°F) and a chilling minimum of -15°C (6°F). Both months see similar levels of precipitation, with September receiving 102 mm (4.0 in) over 8 days and February slightly higher at 105 mm (4.1 in) over 11 days, but February's increased humidity at 88% adds to the cold's biting effect. For a detailed look at February weather specifically, you can visit Deer Isle weather in February.
When comparing the weather in September and March, significant differences emerge in both temperature and precipitation. September experiences milder temperatures, with an average of 16°C (60°F) and a maximum of 22°C (72°F), whereas March is much colder, featuring an average temperature of 0°C (33°F) and a maximum of only 10°C (50°F). Precipitation levels are fairly close, with September receiving 102 mm (4.0 in) over 8 days and March totaling 84 mm (3.3 in) over 9 days. Additionally, humidity levels are relatively high in both months, but March does have a slightly higher average at 85% compared to September's 77%. For a detailed look at March weather in Deer Isle, check out this link: Deer Isle weather in March.
When comparing September and April weather, September typically enjoys milder temperatures, with average highs of 22°C (72°F) and lows of 9°C (48°F), while April experiences significantly cooler conditions, averaging only 5°C (41°F) with a maximum of 14°C (57°F). October tends to be wetter than September, with precipitation levels reaching 157 mm (6.2 in) over 13 days compared to September’s 102 mm (4.0 in) spread across 8 days. Humidity levels are slightly higher in April at 81%, compared to 77% in September. For a more in-depth look at April weather specifics, check out Deer Isle weather in April.
In September, the weather is generally milder with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 22°C (72°F) and an average of 16°C (60°F). This month experiences slightly less precipitation than May, with about 102 mm (4.0 in) over approximately 8 days, along with higher humidity at 77%. In contrast, May features cooler temperatures, with a minimum of 2°C (37°F), an average of 9°C (49°F), and a maximum of 17°C (64°F). Rainfall is comparable, totaling 105 mm (4.1 in) across 11 days, but the humidity is slightly lower at 76%. For more detailed information, check out Deer Isle weather in May.
When comparing the weather in September and June, September tends to be slightly warmer, with average temperatures reaching 16°C (60°F), compared to June's average of 13°C (56°F). Additionally, September experiences a higher maximum temperature of 22°C (72°F), while June tops out at 20°C (69°F). However, June has slightly less precipitation at 87 mm (3.4 in) over 9 days, compared to September's 102 mm (4.0 in) over 8 days, and its humidity is also marginally lower at 74% versus September's 77%. For those interested in more details, you can check Deer Isle weather in June.
In comparing the weather between July and September, both months exhibit similar maximum temperatures, with highs reaching around 22°C (72°F). However, July tends to be slightly warmer overall, with minimum temperatures averaging 12°C (54°F) compared to September's lows of 9°C (48°F). Precipitation levels are relatively close, with September receiving 102 mm (4.0 in) over 8 days, slightly more than July's 92 mm (3.6 in) across 10 days. Interestingly, humidity levels are a bit higher in September at 77%, versus 74% in July. For more detailed insights, you can check Deer Isle weather in July.
In comparing the weather of September to that of August, it’s clear that September is noticeably cooler, with average temperatures dropping from 18°C (64°F) in August to 16°C (60°F). The minimum temperatures also reflect this shift, decreasing from 13°C (57°F) in August to 9°C (48°F) in September. Although both months experience similar precipitation patterns with eight rainy days, September records a higher total rainfall of 102 mm (4.0 in) compared to August's 86 mm (3.4 in). Additionally, September has slightly higher humidity at 77%, compared to 74% in August. For a more in-depth look at August's weather specifics, you can visit Deer Isle weather in August.
In September, the weather is generally milder, with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 22°C (72°F) and an average of 16°C (60°F). The month experiences a fair amount of rain, with 102 mm (4.0 in) of precipitation over 8 days, accompanied by a humidity level of 77%. In contrast, October sees a noticeable drop in temperatures, with minimums of 2°C (35°F) and an average of only 12°C (54°F), peaking at 18°C (65°F). The month is also wetter, with 145 mm (5.7 in) of precipitation over 12 days and increased humidity at 82%. This shift marks a transition to the cooler and wetter conditions typical of autumn. For more detailed information, you can check out the Deer Isle weather in October.
September and November exhibit distinct differences in weather patterns. September features milder temperatures, with averages around 16°C (60°F) and maximums reaching 22°C (72°F), while November sees a significant drop, with average temperatures around 6°C (43°F), and minimums plunging to -11°C (13°F). In terms of precipitation, November is wetter, accumulating 138 mm (5.4 in) over 12 days compared to September's 102 mm (4.0 in) over 8 days. Additionally, November's humidity is slightly higher at 85%, versus September's 77%. For more insights on November weather, check Deer Isle weather in November.
September weather is characterized by milder temperatures, with a minimum of 9°C (48°F) and an average of 16°C (60°F), making it feel quite pleasant. In contrast, December brings significantly colder conditions, with temperatures dropping to a minimum of -17°C (2°F) and an average temperature of just 1°C (34°F). Precipitation also increases from September's 102 mm (4.0 in) over 8 days to December's 155 mm (6.1 in) across 12 days, indicating a wetter month. Additionally, humidity levels rise from 77% in September to 84% in December, adding to the chilly atmosphere. For more details, you can check out Deer Isle weather in December.
As September unfolds on Deer Isle, the weather showcases a pleasant shift, with milder temperatures that make outdoor activities more enjoyable compared to the hotter summer months. While the average temperature hovers around a comfortable 16°C (60°F), the crisp evenings remind us that autumn is on the horizon. Rainfall is moderate, occurring on about eight days, adding a refreshing touch to the landscape without dampening the enthusiasm for exploring the island's natural beauty. With humidity levels at 77%, the air feels fresh yet invigorating, striking a perfect balance for both locals and visitors. For more insights on seasonal changes, check out Deer Isle Climate.