September Weather in Castleton, United States

Last updated: February 24, 2025

In Castleton, United States, September showcases a remarkable shift in weather patterns, with temperatures peaking at a maximum of 32°C (91°F) and dipping to a refreshing average of 17°C (63°F). Evenings can occasionally turn brisk, with a minimum temperature of -1°C (30°F) reminding residents of the upcoming autumn. The month is marked by a total precipitation of 69 mm (2.7 in) over 7 rainy days, creating a lush landscape and contributing to a notable humidity level of 72%. This blend of warmth and occasional rainfall makes September an enchanting transitional month in Castleton.

September Temperature in Castleton

As September unfolds in Castleton, United States, temperatures start to show a gentle transition from the warmth of summer to the crispness of autumn. With a minimum temperature of -1°C (30°F) and an average of 17°C (63°F), locals can expect cool, refreshing days perfect for outdoor activities. The maximum temperatures can still peak at 32°C (91°F), hinting at the lingering warmth of summer. This month serves as a bridge, where the nights become noticeably cooler, setting the stage for the vibrant foliage that October promises. It’s a period of transformation, where the remnants of summer mingle with the early hints of fall, creating a delightful climate for exploration and adventure.

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

The chart illustrates September temperature patterns in Castleton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec232532455766727063513628
Data source: Temperature data for Castleton 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 Castleton

September in Castleton brings a relatively mild dip in precipitation, with 69 mm (2.7 in) of rain falling over just 7 days. This marks a notable decrease from the wetter months of July and August, suggesting a transition into drier autumn conditions. The average rainfall in September is among the lowest of the year, indicating that the region starts to prepare for the more substantial rainfall that typically arrives in October, when totals spike to 139 mm (5.5 in). As summer recedes, Castleton's weather reflects a gradual shift from peak summer storms to quieter, cooler days, reinforcing the cyclical nature of its seasonal climate.

September Precipitation Trends in Castleton

The chart displays monthly precipitation patterns in Castleton, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7986741188780114836913910290
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Castleton

In September, Castleton experiences a slight uptick in humidity, averaging 72%, after a summer low of 64% in August. This marks a transition as the air becomes a bit more saturated following the drier months of July and August. The trend for humidity throughout the year shows a gradual decline from the 89% peak in January, reaching its lowest point in the summer, before beginning to climb again in the fall. As temperatures start to cool, the return to higher humidity levels signals the approach of the wetter months ahead, with October bringing another increase to 81%. This ebb and flow of humidity not only influences the local climate but also sets the stage for the vibrant seasonal changes that characterize Castleton's year.

September Average Humidity in Castleton

This chart illustrates the average monthly humidity levels in Castleton, 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.
JanFebMarAprMayJunJulAugSepOctNovDec90%88%86%84%76%72%67%64%72%81%87%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Castleton

As September rolls into Castleton, the UV Index reflects a notable shift from the scorching heights of summer. With a UV Index of 7, this month is categorized as high exposure, suggesting a burn time of about 25 minutes for unprotected skin. Compared to the very high levels experienced in the peak summer months of June through August, September offers a slight reprieve, though caution is still warranted. This gradual decline in UV intensity continues into October, when the index drops further to 5. As the days shorten and temperatures cool, it’s essential to remain aware of sun safety, particularly in early autumn. For a comprehensive look at UV trends throughout the year, explore Castleton UV Index.

Maximum UV Index Levels in Castleton for September

The chart shows the monthly maximum UV Index (UVI) for Castleton 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.
JanFebMarAprMayJunJulAugSepOctNovDec3458910997532
Data source: Castleton 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 Castleton

As summer wanes, September in Castleton, United States, continues to bask in 289 hours of sunshine, making it a delightful transition into autumn. This month is marked by a notable decrease from the peak summer months of July and August, each boasting an impressive 332 hours of sunlight. Interestingly, September maintains a strong showing compared to the earlier months of the year, showcasing a steady buildup of daylight from the 116 hours in January. With a climate that offers nearly three-quarters of the sun found in the height of summer, September invites residents and visitors alike to relish the lingering warmth and vibrant landscapes, ideal for outdoor activities before the cooler months set in.

Monthly Sunshine Duration in Castleton: September Highlighted

The September sunshine duration represents the total number of hours Castleton 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.
JanFebMarAprMayJunJulAugSepOctNovDec116h155h226h223h271h322h332h332h289h202h159h138h
Data source: Castleton September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Castleton During September

When it comes to enjoying sunny weather in Castleton, United States, September presents a moderate 39% chance of clear skies. This percentage reflects a slight uptick compared to the summer months, where July and August saw lower chances of sunshine at 31% and 35%, respectively. Interestingly, September shares a similar likelihood with April and May, highlighting a potential seasonal transition towards more pleasant weather after the summer heat. Moreover, as the year progresses, the likelihood of sunny days generally fluctuates, peaking in late spring before gradually declining towards the winter months. Overall, September is a promising time for those looking to bask in the warmth of the sun amidst the colors of early fall.

Percentage of Sunny Days in September in Castleton

The chart illustrates the percentage of sunny days in Castleton 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 Castleton experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec34%29%53%39%37%40%31%36%39%36%46%25%
Data source: Castleton September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Castleton in September

As summer wanes into September, Castleton, United States, sees a gentle transition in daylight duration, with the sun gracing the skies for 12 hours each day. This marks a subtle decline from the long, sun-drenched days of July and August, where residents enjoyed 15 and 13 hours of daylight, respectively. The gradual shortening of days in September heralds the shift towards autumn, where daylight continues to decrease as the year progresses into October, bringing with it the familiar ebb and flow of seasons. This rhythmic pattern, from the paler light of winter months with just 9 hours in January and November to the peak brightness of midsummer, reflects nature’s cyclical dance, inviting Castleton’s inhabitants to savor the lingering warmth before embracing the cooler days ahead.

Average Daylight Hours in Castleton for September

The chart illustrates the variation in daylight duration in Castleton throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 21m10h 30m11h 58m13h 27m14h 43m15h 21m15h13h 52m12h 26m10h 57m9h 39m8h 59m
Data source: Castleton daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Castleton

In September, Castleton experiences a gentle breeze with an average wind speed of 2.6 m/s (about 6 mph), aligning closely with the city's typical autumn transition. This slight uptick in wind speed from the quieter months of July and August, which saw lows of 2.2 and 2.1 m/s respectively, suggests a refreshing change as summer wanes. Interestingly, the wind pattern remains fairly stable throughout the year, with January to April showcasing speeds between 2.3 and 3.3 m/s, before tapering to a minimum in the peak of summer. As the year progresses towards the chill of October, September's wind acts as a reminder of the vibrant seasonal shifts, offering a crisp ambiance that perfectly complements the onset of autumn.

Average September Wind Speed in Castleton

The chart displays monthly wind speed patterns in Castleton, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.32.63.32.72.42.82.22.12.6 m/s2.42.52.8
Data source: Castleton September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Castleton Compares to Other Months

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

September and January present stark contrasts in weather patterns. In September, temperatures range from a chilly minimum of -1°C (30°F) to a warm maximum of 32°C (91°F), averaging around 17°C (63°F). The humidity stands at 72%, and the month sees about 69 mm (2.7 in) of precipitation over approximately 7 days. In contrast, January experiences much colder temperatures, with minimums plunging to -30°C (-22°F) and maximums only reaching 16°C (61°F), averaging -5°C (23°F). This month is not only colder but also wetter, with 79 mm (3.1 in) of precipitation spread over 10 days, accompanied by higher humidity at 89%. For more details, you can check Castleton weather in January.

September and February showcase distinct differences in weather patterns. September experiences a comfortable range of temperatures, with a minimum of -1°C (30°F), an average of 17°C (63°F), and a maximum of 32°C (91°F). This month typically sees 69 mm (2.7 in) of precipitation over about 7 days, accompanied by a moderate humidity level of 72%. In contrast, February is much colder, with temperatures dipping to a minimum of -24°C (-11°F) and averaging -4°C (26°F), while highs only reach 21°C (69°F). February is also wetter, receiving 86 mm (3.4 in) of precipitation across 12 days and higher humidity at 88%. For a more detailed look at February weather, you can visit Castleton weather in February.

September and March present contrasting weather patterns characterized by influential temperature ranges and humidity levels. In September, temperatures can fluctuate from a chilly minimum of -1°C (30°F) to a warm maximum of 32°C (91°F), averaging around 17°C (63°F). The month typically receives about 69 mm (2.7 in) of precipitation over 7 days, with a humidity level of 72%. In comparison, March is marked by much colder conditions, with lows plunging to -19°C (-3°F) and highs reaching only 21°C (69°F), averaging around 0°C (32°F). This month sees slightly higher precipitation at 74 mm (2.9 in) over 10 days, accompanied by an increased humidity of 86%. For more insights into weather specifics during this time, you can visit Castleton weather in March.

September and April present distinct weather patterns that highlight the transition between seasons. In September, temperatures range from a chilly minimum of -1°C (30°F) to a warm maximum of 32°C (91°F), with an average of 17°C (63°F). This month experiences relatively low precipitation at 69 mm (2.7 in) over about 7 days, and humidity averages around 72%.

In contrast, April is cooler overall, with temperatures dipping to a minimum of -6°C (22°F) and peaking at 26°C (79°F), yielding an average of 7°C (45°F). It also sees more rainfall, totaling 118 mm (4.7 in) across approximately 14 days, accompanied by higher humidity at 84%. For more detailed insights into April weather, you can visit Castleton weather in April.

When comparing the weather in September and May, we see distinct differences in temperature and precipitation patterns. September generally offers a wider temperature range, with average highs reaching up to 32°C (91°F), while May's average high is slightly lower at 33°C (91°F), but it has a cooler average temperature of 14°C (57°F). In terms of precipitation, May is wetter, averaging 87 mm (3.4 in) over about 13 days, compared to September's 69 mm (2.7 in) over just 7 days. Additionally, May tends to have higher humidity levels at 76%, in contrast to September's 72%. For more detailed insights on May weather, check Castleton weather in May.

In comparing the weather conditions of September and June, September tends to have more variability in temperature, with a minimum as low as -1°C (30°F) and a maximum reaching 32°C (91°F), resulting in an average of 17°C (63°F). In contrast, June's temperatures are more consistently warm, with lows of 4°C (40°F) and highs of 34°C (94°F), leading to an average of 19°C (66°F). While both months experience similar humidity levels at 72%, June sees slightly more rainfall, with 80 mm (3.2 in) over 12 days compared to September's 69 mm (2.7 in) over 7 days. For more detailed information on June weather, visit Castleton weather in June.

In comparing the weather between September and July, notable differences emerge in both temperatures and precipitation. September features a broader temperature range with minimums dipping to -1°C (30°F) and maximums reaching 32°C (91°F), resulting in an average temperature of 17°C (63°F). In contrast, July maintains milder nighttime temperatures at a minimum of 9°C (49°F) and higher daytime highs, averaging 22°C (72°F) with a peak of 37°C (98°F). Precipitation is also more frequent in July, totaling 114 mm (4.5 in) over 12 days compared to September's 69 mm (2.7 in) over 7 days. Interestingly, while September is slightly more humid at 72%, July’s humidity stands at 66%. For further details on the weather patterns in July, visit Castleton weather in July.

In comparing the weather between August and September, September experiences a wider temperature range with minimums dropping down to -1°C (30°F), while August maintains a milder minimum of 7°C (45°F). The average temperature in September is slightly lower at 17°C (63°F) compared to August's warmer average of 21°C (70°F). Although both months see high temperatures reaching near the same maximum, with September peaking at 32°C (91°F) and August at 33°C (92°F), September tends to be wetter, receiving 69 mm (2.7 in) of precipitation over 7 days, whereas August receives 83 mm (3.3 in) over 10 days. Additionally, humidity levels are higher in September at 72%, compared to August's 64%. For more details on August weather, you can refer to Castleton weather in August.

September and October showcase a significant transition in weather patterns. In September, temperatures range from a minimum of -1°C (30°F) to a maximum of 32°C (91°F), averaging around 17°C (63°F), with relatively lower humidity at 72%. The month experiences around 69 mm (2.7 in) of precipitation over just 7 days, indicating a drier climate.

In contrast, October sees a drop in temperatures, with a minimum of -4°C (25°F), averaging 11°C (51°F), and a maximum of 25°C (78°F). This month is notably wetter, accumulating 139 mm (5.5 in) of precipitation over 13 days, coupled with increased humidity levels at 81%. For more detailed insights, check out Castleton weather in October.

September and November exhibit significantly different weather patterns, reflecting the transition from late summer to late fall. In September, temperatures range from a pleasant minimum of -1°C (30°F) to a warm maximum of 32°C (91°F), with an average of 17°C (63°F). The month typically sees about 69 mm (2.7 in) of precipitation over 7 days, and humidity hovers around 72%. In stark contrast, November experiences much colder temperatures, with a minimum dipping to -20°C (-4°F) and a maximum of only 22°C (72°F), resulting in an average temperature of just 2°C (37°F). This month records higher precipitation at 102 mm (4.0 in) over 12 days, alongside increased humidity levels at 87%. For a more detailed look at the November climate in Castleton, you can visit Castleton weather in November.

September and December showcase a striking contrast in weather patterns. In September, temperatures range from a chilly -1°C (30°F) at night to a warm 32°C (91°F) during the day, with an average of 17°C (63°F). The month experiences moderate precipitation of 69 mm (2.7 in) over 7 days, accompanied by a humidity level of 72%. In stark contrast, December plunges to frigid temperatures, with a minimum of -28°C (-18°F) and a slightly higher maximum of 15°C (59°F), averaging around -2°C (28°F). This wintry month also sees increased precipitation at 90 mm (3.5 in) over 11 days and higher humidity at 84%. For more details on the weather in December, visit Castleton weather in December.

Compare Castleton's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Castleton

As September arrives in Castleton, the weather shifts to a delightful blend of warmth and coolness, marking a transition from the sweltering days of summer to the crispness of fall. With temperatures reaching a peak of 32°C (91°F) but averaging a comfortable 17°C (63°F), the month provides a pleasant climate perfect for outdoor activities and enjoying the changing foliage. Rainfall, with about 69 mm spread across approximately 7 days, adds a refreshing touch to the landscape, while the humidity remains relatively high at 72%, contributing to a rich, vibrant atmosphere. This makes September notably different from the preceding summer months, inviting residents and visitors alike to soak in the serene beauty that Castleton has to offer. For more insights, be sure to check out the detailed information on Castleton Climate.