September Weather in Westport, United States

Last updated: February 24, 2025

September in Westport, United States brings a delightful transition from summer to autumn. With maximum temperatures reaching a pleasant 30°C (85°F) and an average of 16°C (60°F), the weather remains inviting for outdoor activities. However, as the month progresses, minimum temperatures can drop to 6°C (43°F), reminding us of the cooler days ahead. The region experiences about 106 mm (4.2 in) of precipitation over 10 days, contributing to the lush landscapes typical of this time of year. Humidity hovers around 74%, enhancing the refreshing, crisp air that characterizes early fall in Westport.

September Temperature in Westport

In September, Westport, United States, experiences a delightful transition into early autumn, characterized by mild temperatures that invite outdoor activities. The month sees a minimum temperature of 6°C (43°F) and an average of 16°C (60°F), gently warming up to a comfortable maximum of 30°C (85°F). This moderate climate marks a shift from the summer heat of August, where maximums reached 32°C (90°F), to a more temperate fall season. As daylight hours shorten, the crispness in the air becomes more pronounced, setting the perfect backdrop for enjoying fall foliage and seasonal festivities. This blend of warmth and cool breezes makes September a favorite time for both locals and visitors to embrace the charm of Westport.

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

The chart illustrates September temperature patterns in Westport, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec444346505459616260534843
Data source: Temperature data for Westport 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 Westport

In September, Westport experiences a noticeable uptick in precipitation, with 106 mm (4.2 in) falling over 10 days—suggesting the onset of the wetter autumn season. This is a significant increase from the exceptionally dry months of July and August, which saw only 13 mm (0.5 in) and 12 mm (0.5 in), respectively. As the summer heat fades, September’s rainfall prepares the landscape for the arrival of the heavier showers typical of October and November. This shift marks a transition, where the air grows crisper and the lush greenery that defines Westport flourishes, influenced by the gradual rise in precipitation that marks autumn's approach.

September Precipitation Trends in Westport

The chart displays monthly precipitation patterns in Westport, 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.
JanFebMarAprMayJunJulAugSepOctNovDec25917315813966581312106173267231
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Westport

September in Westport marks a subtle transition in humidity levels, showcasing a drop to 74%—a notable decrease from the summer highs. This month stands out as part of a gradual decline that begins in August, where humidity peaks at 73%, the lowest of the year, before creeping back up in October to 83%. The overall trend from January through June reveals a relatively high humidity range, fluctuating around 84%, while the latter months of the year, particularly November and December, see a resurgence in moisture, culminating at 87%. This cycle underscores Westport's shifting atmospheric dynamics as it gracefully eases from the warmth of summer into the crispness of fall.

September Average Humidity in Westport

This chart illustrates the average monthly humidity levels in Westport, 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.
JanFebMarAprMayJunJulAugSepOctNovDec86%84%85%83%84%84%82%73%74%83%86%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Westport

As summer transitions into autumn, the UV Index in Westport experiences a noticeable decline, yet remains significant in September with a value of 7, categorized as high. This change signals a shift from the intense summer sun, which peaked at 9 in May through August, where a mere 15 minutes of exposure could lead to burns. In contrast, September offers a more forgiving burn time of 25 minutes. This trend reflects the gradual decrease in solar intensity as daylight shortens, yet caution is still warranted, particularly for those spending extended periods outdoors. To stay informed about UV levels and protect your skin, check out the detailed forecasts at Westport UV Index.

Maximum UV Index Levels in Westport for September

The chart shows the monthly maximum UV Index (UVI) for Westport 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.
JanFebMarAprMayJunJulAugSepOctNovDec235699987531
Data source: Westport 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 Westport

As summer transitions into autumn, September in Westport brings a generous 262 hours of sunshine, a lovely continuation of the sun-kissed days experienced in the peak summer months. Following the vibrant July and August, which boasted 359 and 329 hours respectively, September's sunlight remains abundant, marking a significant drop yet still surpassing the early months of the year. This trend highlights the region's gradual shift towards cooler temperatures while still enjoying ample daylight, with a noticeable decline in sunshine as the year approaches winter. The warmth lingers, inviting residents and visitors alike to bask in the beautiful autumn glow before the shorter days of October set in, reminding us of the fleeting nature of summer's charm.

Monthly Sunshine Duration in Westport: September Highlighted

The September sunshine duration represents the total number of hours Westport 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.
JanFebMarAprMayJunJulAugSepOctNovDec87h137h218h238h305h328h359h329h262h205h130h105h
Data source: Westport September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Westport During September

In Westport, the likelihood of sunny weather in September maintains a moderate pace, with a 32% chance of sun—a figure that reflects its position on the cusp of summer's warmth and autumn's arrival. As the seasons transition, September's sunshine likelihood is notably higher than the winter months of January and February, which hover around 13% and 18%, respectively. Interestingly, the sun's presence in September aligns closely with both May and August, suggesting a consistent trend where late summer and early autumn share similar skies. As residents and visitors savor the fading warmth, September offers a blend of sunny days amid the encroaching cooler weather, making it a delightful time for outdoor activities in Westport.

Percentage of Sunny Days in September in Westport

The chart illustrates the percentage of sunny days in Westport 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 Westport experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec13%18%30%43%32%42%42%36%32%26%13%16%
Data source: Westport September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Westport in September

As summer draws to a close, September in Westport, United States, ushers in a noticeable shift in daylight hours, offering about 12 hours of sunlight. While this marks a gradual decline from the longer days of July and August, when the sun graced the sky for 15 and 14 hours respectively, it still reflects the lingering warmth of late summer. This transitional month serves as a bridge, paving the way for the shorter days of autumn that follow, where daylight dips to 10 hours in October and further decreases through the winter months. The September sunlight allows residents to savor the tail end of summer while preparing for the cozy shifts of fall, making it a month of both reflection and anticipation.

Average Daylight Hours in Westport for September

The chart illustrates the variation in daylight duration in Westport throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 59m10h 18m11h 57m13h 38m15h 5m15h 48m15h 24m14h 6m12h 29m10h 48m9h 19m8h 33m
Data source: Westport daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Westport

In Westport, United States, the September winds carry a gentle breeze with an average speed of 3.0 m/s (7 mph), slightly cooling down after the summer months. This modest shift reflects the overall trend of diminishing wind speeds as the year progresses—peaking at 4.1 m/s (9 mph) in the cooler months of November. The springtime and early summer months show a bit of variability, with April and June experiencing the calmest winds at 2.6 m/s (6 mph) and 2.9 m/s (7 mph), respectively. By September, the transition begins in earnest as fall approaches, leading to more stable but softer winds, setting the scene for a picturesque autumn in Westport.

Average September Wind Speed in Westport

The chart displays monthly wind speed patterns in Westport, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.64.13.62.63.22.93.53.13.0 m/s3.74.13.7
Data source: Westport September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Westport Compares to Other Months

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

In September, the weather tends to be warmer, with temperatures ranging from a minimum of 6°C (43°F) to a maximum of 30°C (85°F), and an average of 16°C (60°F). The month experiences moderate rainfall, with around 106 mm (4.2 in) of precipitation over about 10 days and a humidity level of 74%. In contrast, January brings much colder temperatures, with a minimum of -5°C (24°F) and a maximum of 14°C (57°F), averaging 7°C (44°F). The winter month is significantly wetter, receiving about 259 mm (10.2 in) of precipitation over 17 days, and sees a higher humidity of 86%. For more detailed information on January weather, you can visit Westport weather in January.

September and February present contrasting weather experiences. In September, temperatures range from a minimum of 6°C (43°F) to a comfortable average of 16°C (60°F), peaking at 30°C (85°F). The month sees about 106 mm (4.2 in) of precipitation over approximately 10 days, with a humidity level of 74%. In stark contrast, February brings much cooler conditions, with temperatures dipping to a minimum of -3°C (27°F) and averaging around 6°C (43°F), reaching a maximum of 15°C (60°F). It is also wetter, with 173 mm (6.8 in) of precipitation spread over 18 days and higher humidity at 84%. For more details on February weather, visit Westport weather in February.

When comparing the weather in September and March, notable differences emerge. September typically offers milder conditions with temperatures ranging from a minimum of 6°C (43°F) to a maximum of 30°C (85°F), resulting in a pleasant average of 16°C (60°F). However, it sees around 106 mm (4.2 in) of precipitation over approximately 10 days, alongside a humidity level of 74%. In contrast, March experiences cooler temperatures, with a minimum of -1°C (30°F) and a maximum of 23°C (74°F), averaging 8°C (46°F). This month has higher precipitation, totaling about 158 mm (6.2 in) across 17 days, and increased humidity at 85%. For a detailed look at the weather patterns during March, you can refer to Westport weather in March.

When comparing the weather in September and April, we can see distinct differences in temperature and precipitation patterns. September typically boasts warmer temperatures, with a minimum of 6°C (43°F) and an average of 16°C (60°F), peaking at a comfortable 30°C (85°F). In contrast, April starts cooler, with a minimum temperature of 1°C (35°F) and an average of only 10°C (50°F), though it can still reach a high of 27°C (80°F).

In terms of precipitation, April experiences more rainfall, totaling 139 mm (5.5 in) over about 15 days, compared to September's 106 mm (4.2 in) spread over 10 days. Additionally, the humidity levels are generally higher in April at 83%, compared to September's 74%. For a detailed look at what April weather has in store, you can check out Westport weather in April.

September and May showcase distinct weather patterns, highlighting the transition between summer and autumn. In September, temperatures range from a minimum of 6°C (43°F) to a maximum of 30°C (85°F), with an average temperature of 16°C (60°F). The month experiences increased precipitation, totaling 106 mm (4.2 in) over approximately 10 days, while the humidity sits at 74%. In contrast, May offers a slightly cooler climate, with temperatures ranging from a minimum of 5°C (42°F) to a maximum of 29°C (85°F), averaging 12°C (55°F). Precipitation in May is less frequent at 66 mm (2.6 in) over 10 days, but humidity is higher at 84%. This comparison underscores how September generally feels warmer and wetter compared to the cooler and drier conditions of May. For more information, check out Westport weather in May.

In comparing the weather of September to that of June, September tends to offer a wider temperature range, with minimums as low as 6°C (43°F) and maximums reaching up to 30°C (85°F), while June can peak dramatically at 40°C (104°F), though its average temperatures are slightly lower with a minimum of 7°C (44°F) and an average of 15°C (59°F). Precipitation in September is notably higher, with 106 mm (4.2 in) falling over about 10 days, compared to June's 58 mm (2.3 in) over about 8 days. Additionally, June's humidity is marginally higher at 84%, providing a more humid feel than September's average of 74%. For a deeper look into June's weather specifics, you can visit Westport weather in June.

When comparing the weather in September and July, September tends to offer a broader range of temperatures, with nightly lows dipping to around 6°C (43°F) and daytime highs reaching up to 30°C (85°F). This month experiences approximately 106 mm (4.2 in) of precipitation over about 10 days, bringing a noticeable increase in moisture, with humidity levels around 74%. In contrast, July is generally warmer, with a minimum temperature of 10°C (51°F) and a maximum of 28°C (82°F). This month sees significantly less rain, only about 13 mm (0.5 in) over 3 days, and higher humidity at 82%. For more detailed information on the weather during this month, you can check Westport weather in July.

In comparing the weather of September to August, we see a notable shift in temperature and precipitation patterns. September exhibits a broader temperature range, with minimums dropping to 6°C (43°F) and maximums reaching up to 30°C (85°F), compared to August, where the minimum temperature is 10°C (51°F) and maximum is slightly higher at 32°C (90°F). Additionally, September experiences significantly more precipitation, totaling 106 mm (4.2 in) over 10 days, whereas August only sees 12 mm (0.5 in) across 3 days. Humidity levels remain similar, with September at 74% and August at 73%. For more details about August weather, you can visit Westport weather in August.

September and October present a noticeable shift in weather patterns. In September, temperatures range from a minimum of 6°C (43°F) to a maximum of 30°C (85°F), with an average of 16°C (60°F). The month experiences 106 mm (4.2 in) of precipitation over approximately 10 days, while humidity sits at 74%. In contrast, October sees cooler temperatures, with a minimum of 2°C (36°F) and a maximum of 22°C (72°F), resulting in a lower average of 12°C (53°F). Precipitation increases significantly to 173 mm (6.8 in) over 13 days, along with a rise in humidity to 83%. This transformation highlights the transition from the warm, relatively dry conditions of September to the cooler and wetter climate of October. For more details, you can check Westport weather in October.

In September, the weather offers a wider range of temperatures, with minimums around 6°C (43°F) and maximums reaching up to 30°C (85°F), resulting in an average of 16°C (60°F). However, it also sees a fair amount of rain, totaling 106 mm (4.2 in) over 10 days, with a humidity level of 74%. In contrast, November brings much cooler temperatures, with minimums dropping to 0°C (33°F) and maximums capping at 16°C (62°F), averaging just 9°C (48°F). Additionally, November is significantly wetter, receiving 267 mm (10.5 in) of precipitation over 18 days, and the humidity rises to 86%. For more details on November's weather patterns, you can visit Westport weather in November.

In September, the weather is generally mild and comfortable, with average temperatures ranging from a minimum of 6°C (43°F) to a maximum of 30°C (85°F). This month sees around 106 mm (4.2 in) of precipitation over approximately 10 days, alongside a humidity level of 74%. By contrast, December brings a notable shift, with much colder temperatures averaging between -3°C (27°F) and 14°C (57°F). Rainfall is significantly higher in December, measuring 231 mm (9.1 in) over 19 days, and the humidity increases to 87%. For more detailed insights, check out Westport weather in December.

Compare Westport's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Westport

As September rolls in, Westport transitions into a more mild and temperate climate, standing out from the sweltering summer months. The cool breezes and refreshing humidity create a comfortable atmosphere, making it ideal for outdoor activities. However, the increase in rainfall also marks this month as one of the wetter periods, with several days of precipitation reminding us that autumn is just around the corner. This blend of warmth and moisture adds a unique charm to Westport, providing a perfect backdrop for those looking to experience the beauty of the season. For more insights into year-round weather patterns, check out Westport Climate.