September Weather in Vermont, United States

Last updated: February 24, 2025

In September, Vermont experiences a captivating transition into autumn, marked by a maximum temperature of 33°C (91°F) and an average of 18°C (65°F), providing a pleasant climate for outdoor activities. As cooler nights set in, temperatures can dip to a minimum of 3°C (37°F), signaling the arrival of crisp evenings. The month is characterized by 119 mm (4.7 in) of precipitation over 10 days, contributing to the lush greenery of the region. With a humidity level of 79%, the air is often rich and vibrant, enhancing the beauty of the fall foliage that Vermont is renowned for.

September Temperature in Vermont

In September, Vermont begins to embrace the crispness of early autumn, with temperatures transitioning from the warmth of summer. The minimum temperature settles at 3°C (37°F), while the average climbs to a comfortable 18°C (65°F), providing a delightful reprieve from the summer heat. As the month progresses, daily highs can reach up to 33°C (91°F), particularly in the early days, reminding us of summer's lingering warmth. This contrast creates a vibrant atmosphere, perfect for enjoying the beautiful fall foliage that Vermont is renowned for. Overall, September marks a significant shift, as the landscape transforms and prepares for the cooler months ahead.

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

The chart illustrates September temperature patterns in Vermont, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec212236466071757165513629
Data source: Temperature data for Vermont generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Vermont

In September, Vermont experiences a notable increase in precipitation, with 119 mm (4.7 in) of rain falling over approximately 10 days. This trend continues the wet pattern established in the summer months, where August recorded 113 mm of precipitation. Following the lush greenery of May and June, which saw the highest totals, September serves as a transition, maintaining significant moisture before the drier autumn months ahead. The steady rainfall is vital for sustaining the vibrant fall foliage that Vermont is renowned for, ensuring that the landscape is not only beautiful but also nourished as it prepares for the colder weeks to come.

September Precipitation Trends in Vermont

The chart displays monthly precipitation patterns in Vermont, 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.
JanFebMarAprMayJunJulAugSepOctNovDec50565893135123871131191174344
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Vermont

As the summer fades away, September brings a slight uptick in humidity levels in Vermont, rising to 79%. This marks a transition from the drier conditions of August, which recorded a low of 76%. Observing the trend throughout the year, it's clear that winter months feature consistently high humidity at 85% or above, while the summer months, particularly July and August, present lower readings in the high 70s. As autumn approaches, humidity levels begin to stabilize, settling into a more moderate range before the winter months reintroduce the characteristic dampness of the season. The shift in September indicates a subtle but important blend of summer's warmth with the impending crispness of fall.

September Average Humidity in Vermont

This chart illustrates the average monthly humidity levels in Vermont, 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.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%85%85%78%80%78%76%79%83%88%82%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Vermont

In September, Vermont experiences a notable continuation of the summer's intensity, with a UV Index of 8, classified as very high. This value indicates that while the scorching days of July and June may be behind us, the need for sun protection remains crucial, as unprotected exposure can lead to sunburn in just 15 minutes. The trend from July’s peak at 10 gradually decreases through August and into September, yet it still demands vigilance against UV radiation. With the arrival of fall, this transition highlights the importance of staying informed about UV levels throughout the year, as they can fluctuate significantly even in the more temperate months. For more insights on UV exposure in Vermont, visit Vermont UV Index.

Maximum UV Index Levels in Vermont for September

The chart shows the monthly maximum UV Index (UVI) for Vermont 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.
JanFebMarAprMayJunJulAugSepOctNovDec34589101098532
Data source: Vermont 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 Vermont

As summer gives way to autumn, September in Vermont welcomes a delightful 262 hours of sunshine, marking a gentle step back from the sun-soaked days of July, which boasts the year's peak at 356 hours. This month showcases a noticeable decline in daylight, with the lush greens of summer transitioning into vibrant autumn hues. Despite the decrease, September remains bright, outshining the earlier months of the year and hinting at the crisp, refreshing days to come. With each hour of sunlight, Vermont's landscape seems to bask in a warm glow, inviting residents and visitors alike to revel in the picturesque scenery during this beautiful transitional period.

Monthly Sunshine Duration in Vermont: September Highlighted

The September sunshine duration represents the total number of hours Vermont 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.
JanFebMarAprMayJunJulAugSepOctNovDec126h194h228h237h264h324h356h330h262h203h185h176h
Data source: Vermont September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Vermont During September

As summer draws to a close, September in Vermont ushers in a notable increase in sunny days with a 61% chance of sunshine. This shift marks a significant rise from the wetter months of July and August, which see lower probabilities of clear skies at 45% and 57%, respectively. The trend reflects a transition from the more humid summer season, with September setting the stage for crisp and clear autumn days. With sunshine more likely than not, it's the perfect time for outdoor activities amid the stunning fall foliage that Vermont is famous for. However, as October approaches, the likelihood of sun dips to 36%, reminding us of the changing seasons ahead.

Percentage of Sunny Days in September in Vermont

The chart illustrates the percentage of sunny days in Vermont 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 Vermont experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec25%35%44%35%35%52%45%57%61%36%41%34%
Data source: Vermont September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Vermont in September

As September unfolds in Vermont, the state experiences a gentle decline in daylight, with 12 hours of sunlight gracing each day. This marks a subtle transition from the peak summer months of June and July, where daylight reached a vibrant 15 hours and 14 hours, respectively. Throughout the spring, daylight steadily lengthened, culminating in May with 14 hours. However, as autumn approaches, the days begin to shorten more noticeably, paving the way for the serene but brisk days of October and November, which only offer 10 hours and 9 hours of daylight. This gradual shift not only signifies the changing seasons but also invites Vermonters to savor the last remnants of summer before the cozy embrace of fall sets in.

Average Daylight Hours in Vermont for September

The chart illustrates the variation in daylight duration in Vermont throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 23m10h 31m11h 57m13h 26m14h 41m15h 18m14h 57m13h 51m12h 26m10h 58m9h 41m9h 2m
Data source: Vermont daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Vermont

As summer transitions into autumn, September in Vermont experiences a subtle increase in wind speed, averaging 3.3 m/s (7 mph). This marks a slight uptick from the summer months, where winds hovered around their lowest, peaking at 2.8 m/s (6 mph) in July and 2.6 m/s (6 mph) in August. Compared to the earlier months of the year, September's breezes echo the promise of change, setting the stage for the milder gusts typical of October, which also averages at 3.3 m/s (7 mph). As the landscape transforms with the vibrant colors of fall foliage, the gentle winds remind us of the beautiful transition that characterizes this time of year in New England.

Average September Wind Speed in Vermont

The chart displays monthly wind speed patterns in Vermont, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.23.44.13.73.53.02.82.63.3 m/s3.34.03.9
Data source: Vermont September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Vermont Compares to Other Months

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

September and January present two starkly contrasting weather scenarios. In September, temperatures range from a mild 3°C (37°F) at night to a warm 33°C (91°F) during the day, accompanied by 119 mm (4.7 in) of rainfall over approximately 10 days and a humidity level of 79%. In contrast, January brings a frigid chill, with temperatures dropping as low as -32°C (-26°F) and an average of -6°C (21°F), along with significantly reduced precipitation of 50 mm (2.0 in) over 8 days and a humidity level of 85%. For more details on January's weather, you can explore Vermont weather in January.

September presents a warmer and more variable climate, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 33°C (91°F) and an average of 18°C (65°F). With 119 mm (4.7 in) of precipitation spread over 10 days and a humidity level of 79%, September often feels humid and wet. In contrast, February experiences bitterly cold temperatures, with a minimum of -33°C (-26°F) and a maximum of 20°C (69°F), averaging -5°C (23°F). The month has significantly less precipitation at 56 mm (2.2 in) over 9 days, yet it maintains a higher humidity level of 85%. For those interested in exploring more about February weather, check out Vermont weather in February.

The weather comparison between September and March reveals significant differences in temperature and climate conditions. In September, temperatures range from a minimum of 3°C (37°F) to a maximum of 33°C (91°F), with an average of 18°C (65°F). This month experiences relatively high humidity at 79% and sees about 119 mm (4.7 in) of precipitation over approximately 10 days. In stark contrast, March can be quite chilly, with temperatures dipping as low as -25°C (-12°F) and peaking at 23°C (73°F), averaging around 2°C (36°F). March is notably drier, with only 58 mm (2.3 in) of precipitation over about 8 days and higher humidity at 85%. For a detailed look at what to expect, check out Vermont weather in March.

When comparing the weather in September and April, notable differences emerge in temperature and conditions. September enjoys a warmer climate, with average temperatures ranging from a chilly 3°C (37°F) at night to a warm 33°C (91°F) during the day, while April features colder temperatures, with a minimum of -8°C (17°F) and a maximum of 27°C (80°F). Precipitation is slightly higher in September, averaging 119 mm (4.7 in) over 10 days compared to April's 93 mm (3.7 in) over 12 days. Humidity levels are also higher in April at 85%, compared to 79% in September. For more detailed insights into April's weather, you can check the following link: Vermont weather in April.

September and May offer distinct weather experiences. In September, temperatures range from a cool 3°C (37°F) at night to a warm 33°C (91°F) during the day, with an average of 18°C (65°F). The month sees about 119 mm (4.7 in) of precipitation over 10 days, paired with a humidity level of 79%. In contrast, May features a slightly cooler minimum temperature of -1°C (31°F) and an average of 15°C (60°F), with highs reaching 34°C (94°F). Although May experiences more precipitation at 135 mm (5.3 in) over 14 days, it maintains a comparable humidity level of 78%. For a deeper dive into the weather specifics, check out Vermont weather in May.

When comparing the weather in September and June, notable differences emerge in temperature and precipitation patterns. September typically experiences a wider temperature range, with minimums dropping to 3°C (37°F) and maximums reaching up to 33°C (91°F), culminating in an average of 18°C (65°F). In contrast, June offers milder temperatures with a minimum of 8°C (47°F) and a higher average of 21°C (71°F), peaking at 34°C (94°F). Precipitation is slightly higher in June, totaling 123 mm (4.9 in) over 12 days, compared to September’s 119 mm (4.7 in) across 10 days, and both months share similar humidity levels around 79-80%. For more detailed information on June weather in Vermont, you can visit Vermont weather in June.

When comparing the weather in September and July, several differences stand out. September experiences a greater temperature range, with a minimum of 3°C (37°F) and a maximum of 33°C (91°F), leading to an average temperature of 18°C (65°F). In contrast, July maintains a warmer overall climate, with temperatures ranging from a minimum of 13°C (55°F) to a maximum of 35°C (96°F) and an average of 24°C (75°F). Additionally, September sees more precipitation, totaling 119 mm (4.7 in) over 10 days, compared to July's 87 mm (3.4 in) under the same number of rainy days. Both months display similar humidity levels, with September at 79% and July at 78%. For more detailed information about July weather, check out Vermont weather in July.

In comparing the weather between September and August, September experiences a broader temperature range, with minimums dropping to 3°C (37°F) and an average of 18°C (65°F), while August maintains milder lows at 10°C (50°F) and a higher average of 22°C (71°F). Both months feature similar maximum temperatures, peaking at around 32°C (91°F), but September sees slightly more precipitation at 119 mm (4.7 in) over 10 days, compared to August's 113 mm (4.4 in) over 11 days. The humidity also rises slightly in September to 79%, compared to 76% in August, indicating a slightly more humid feel as summer transitions to fall. For a detailed look at August weather, you can visit Vermont weather in August.

September weather tends to be warmer, with an average temperature of 18°C (65°F) and maximum highs reaching up to 33°C (91°F). However, this month also experiences considerable rainfall, totaling 119 mm (4.7 in) over around 10 days, with humidity levels at 79%. In contrast, October brings a notable drop in temperatures, featuring a minimum of -5°C (23°F) and an average of 11°C (51°F), although it still boasts maximum temperatures around 30°C (86°F). Precipitation remains similar at 117 mm (4.6 in) but occurs over a slightly longer period of 13 days, with humidity increasing to 83%. For more detailed information, you can explore Vermont weather in October.

September and November present a stark contrast in weather conditions. In September, temperatures range from a mild 3°C (37°F) at night to a warm 33°C (91°F) during the day, with an average temperature of 18°C (65°F). The month sees significant rainfall, totaling 119 mm (4.7 in) over about 10 days, alongside a humidity level of 79%. In contrast, November experiences much colder temperatures, with a minimum of -16°C (4°F) and a maximum of 22°C (72°F), averaging just 2°C (37°F). Precipitation decreases to 43 mm (1.7 in) over 8 days, while humidity rises to 88%, creating a crisp atmosphere. For more specific insights about November weather, check out Vermont weather in November.

September and December present striking contrasts in weather conditions. In September, temperatures range from a mild 3°C (37°F) at night to a hot 33°C (91°F) during the day, with an average temperature of 18°C (65°F). The month sees significant rainfall, with 119 mm (4.7 in) of precipitation over about 10 days and humidity levels hovering around 79%. In contrast, December brings much colder weather, characterized by a starkly lower range of temperatures from a chilling minimum of -23°C (-8°F) to a maximum of 19°C (66°F), with an average of -2°C (29°F). Precipitation decreases to 44 mm (1.7 in) over 6 days, with humidity slightly higher at 81%. For more insights on what to expect during this winter month, you can explore Vermont weather in December.

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Conclusion: What to Expect From September Weather in Vermont

As summer fades, September in Vermont ushers in a delightful transition, marked by mild temperatures and a noticeable drop in extremes. The days are still warm, occasionally peaking at 33°C (91°F), but the average settles comfortably around 18°C (65°F), offering a refreshing change. This month sees increased rainfall, with about 119 mm distributed over 10 days, contributing to the lush landscapes that characterize this season. The humidity hovers at 79%, adding a crispness to the air that is especially refreshing after the heat of summer. For a deeper dive into the weather patterns year-round, explore Vermont Climate.