September Weather in Castel Gandolfo, Italy

Last updated: March 24, 2025

September in Castel Gandolfo, Italy offers a delightful mix of warm days and cooler evenings, perfect for exploring this charming lakeside town. With maximum temperatures reaching 32°C (90°F) and an average of 21°C (70°F), visitors can enjoy plenty of sunshine, although evenings can dip to a refreshing 8°C (47°F). Expect some rain with an average precipitation of 106 mm (4.2 in) over 10 days, contributing to a comfortable 65% humidity. This transition month showcases the beauty of early autumn, making it an ideal time for outdoor activities and soaking in the scenic vistas of the surrounding countryside.

September Temperature in Castel Gandolfo

In September, Castel Gandolfo experiences a delightful transition from the summer heat to the crispness of fall. With minimum temperatures around 8°C (47°F) and average highs peaking at 32°C (90°F), this charming Italian town offers a perfect climate for both relaxation and exploration. The pleasant average temperature of 21°C (70°F) provides a comfortable backdrop for outdoor activities, while the cooling evenings hint at the impending autumn. Compared to the blistering August temperatures, September's weather signifies a welcome respite, making it an ideal time to appreciate the stunning landscapes and historical treasures of this picturesque lakeside destination.

September Weather in Castel Gandolfo: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Castel Gandolfo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec444850566472777870615547
Data source: Temperature data for Castel Gandolfo 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 Castel Gandolfo

September marks a notable shift in precipitation patterns in Castel Gandolfo, Italy, with an increase to 106 mm (4.2 in)—the highest amount since May. This month typically experiences around 10 days of rain, highlighting a transition as summer fades and autumn approaches. The significant uptick in rainfall contrasts sharply with the preceding dry summer months of July and August, which recorded just 31 mm (1.2 in) and 28 mm (1.1 in), respectively. As the region gears up for the wetter season ahead, September's precipitation not only nourishes the landscape but also sets the stage for the lush colors of fall, marking a vibrant time for nature enthusiasts and visitors alike.

September Precipitation Trends in Castel Gandolfo

The chart displays monthly precipitation patterns in Castel Gandolfo, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7392947589473128106106191170
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Castel Gandolfo

In September, Castel Gandolfo experiences a moderate humidity level of 65%, marking a slight increase from the drier months of July and August, which see lows of 57% and 53% respectively. This uptick heralds the start of autumn, where humidity begins to rise again as the year progresses toward its wetter months. Generally, the trend reveals that humidity levels are relatively high in the winter months, peaking at 84% in January and December. Interestingly, the spring and summer months showcase a noticeable decline, with July and August offering the most refreshing respite before humidity levels gradually climb back up in the fall. Overall, September serves as a gentle transition, inviting cooler, more humid days ahead.

September Average Humidity in Castel Gandolfo

This chart illustrates the average monthly humidity levels in Castel Gandolfo, 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.
JanFebMarAprMayJunJulAugSepOctNovDec84%76%69%70%70%61%57%53%65%75%82%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Castel Gandolfo

In September, Castel Gandolfo experiences a UV Index of 8, categorizing the sun exposure as very high. This marks a slight decrease from the peak summer months of June and July, when the UV Index reached a maximum of 10. Despite this drop, sunbathers should still be cautious, as the recommended burn time is a mere 15 minutes. This trend reflects a gradual transition into the milder autumn season, with the UV Index steadily decreasing from its summer highs, yet still remaining significant enough to warrant protection. As you bask in the fading warmth of summer, remember to stay vigilant and safeguard your skin. For more information on UV conditions, visit Castel Gandolfo UV Index.

Maximum UV Index Levels in Castel Gandolfo for September

The chart shows the monthly maximum UV Index (UVI) for Castel Gandolfo 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.
JanFebMarAprMayJunJulAugSepOctNovDec34579101098642
Data source: Castel Gandolfo 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 Castel Gandolfo

As summer gracefully transitions into autumn, September in Castel Gandolfo, Italy, offers a delightful balance of warmth and sunshine with 338 hours of sunshine, making it a splendid time to enjoy the scenic beauty of this lakeside town. While the peak summer months of July and June bask in an impressive 430 and 415 hours of sunlight respectively, September retains a generous amount of sunshine compared to the earlier months of the year. This trend reveals how autumn invites a soft, golden hue to the landscapes without the sweltering heat of summer. With October trailing closely with 314 hours, the fading summer sun beckons visitors to relish outdoor adventures and the breathtaking views that Castel Gandolfo so famously offers.

Monthly Sunshine Duration in Castel Gandolfo: September Highlighted

The September sunshine duration represents the total number of hours Castel Gandolfo 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.
JanFebMarAprMayJunJulAugSepOctNovDec202h260h327h355h400h415h430h398h338h314h246h244h
Data source: Castel Gandolfo September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Castel Gandolfo During September

When considering the likelihood of sunny weather in September in Castel Gandolfo, Italy, it's important to recognize a noticeable trend from the summer months leading into autumn. September boasts a 53% chance of sunshine, marking a slight dip from the peak of 73% in August, but still offering a respectable opportunity for clear skies. This month's weather is characteristic of a transition, as the warmth of summer gradually yields to cooler autumn breezes. Compared to earlier months, September stands out as a favorable time for outdoor activities, especially when juxtaposed with the declining probabilities in October (41%) and November (33%). Hence, while not as bright as the heart of summer, September still presents a delightful mix of warmth and sun.

Percentage of Sunny Days in September in Castel Gandolfo

The chart illustrates the percentage of sunny days in Castel Gandolfo 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 Castel Gandolfo experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec35%57%58%44%46%59%70%74%53%41%33%48%
Data source: Castel Gandolfo September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Castel Gandolfo in September

As the summer sun begins to wane, September in Castel Gandolfo, Italy, offers a beautiful transition with 12 hours of daylight. This month stands as a bridge between the long, sun-drenched days of summer and the shorter, cooler days of fall. Following the peak daylight of 15 hours in June, September's sunlight gradually recedes, mirroring nature's shift towards autumn. With each passing day becoming slightly shorter, the fading daylight creates a serene atmosphere ideal for enjoying the vibrant autumn colors that soon blanket the region. This subtle decrease in daylight prepares the landscape for the cozy, reflective months ahead, making September a time of both beauty and transition.

Average Daylight Hours in Castel Gandolfo for September

The chart illustrates the variation in daylight duration in Castel Gandolfo throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 31m10h 35m11h 57m13h 21m14h 32m15h 8m14h 49m13h 46m12h 26m11h 2m9h 49m9h 11m
Data source: Castel Gandolfo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Castel Gandolfo

As summer fades in Castel Gandolfo, Italy, September brings a gentle transition in its winds. The average wind speed for this month drops to a soothing 1.7 m/s (4 mph), the calmest of the year, inviting a sense of tranquility after the bustling summer crowds. This decrease from the summer highs of 2.4 m/s in July and August signals the onset of autumn, as the winds begin to mellow. The trend of diminishing gusts continues into October, where speeds rise slightly to 2.2 m/s. Such subtle shifts reflect not only the changing seasons but also the serene ambiance that envelops this picturesque lakeside town, offering visitors a peaceful retreat amidst the changing colors of fall.

Average September Wind Speed in Castel Gandolfo

The chart displays monthly wind speed patterns in Castel Gandolfo, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.72.32.02.12.41.82.42.21.7 m/s2.22.42.3
Data source: Castel Gandolfo September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Castel Gandolfo Compares to Other Months

The weather in Castel Gandolfo 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 Castel Gandolfo and find detailed weather information for every month.

In September, temperatures in Castel Gandolfo generally range from a minimum of 8°C (47°F) to a maximum of 32°C (90°F), with an average of 21°C (70°F). The month experiences a noticeable amount of rainfall, totaling 106 mm (4.2 in) over about 10 days, and humidity levels hover around 65%. In contrast, January brings much cooler temperatures, with a minimum of -6°C (21°F), an average of 7°C (44°F), and a maximum of 18°C (64°F). The precipitation decreases to 73 mm (2.9 in) over 9 days, but the humidity rises significantly to 84%. For more detailed information, you can visit Castel Gandolfo weather in January.

September and February present stark contrasts in weather. In September, temperatures range from a moderate 8°C (47°F) at night to a warm 32°C (90°F) during the day, with an average of 21°C (70°F). This month sees about 106 mm (4.2 in) of rainfall over 10 days, combined with a humidity level of 65%. In contrast, February experiences much colder temperatures, with a minimum of -12°C (11°F) and a maximum of 20°C (68°F), resulting in a much cooler average of 9°C (48°F). The precipitation in February is slightly lower at 92 mm (3.6 in) over 9 days and is accompanied by higher humidity at 76%. For more details on February weather, you can check Castel Gandolfo weather in February.

September and March showcase contrasting weather patterns, reflective of their seasonal transitions. In September, temperatures range from a mild 8°C (47°F) at night to a warm 32°C (90°F) during the day, with an average of 21°C (70°F). This month sees around 106 mm (4.2 in) of precipitation spread across 10 days, paired with a humidity level of 65%. In comparison, March is much cooler, with temperatures dipping to a chilly -11°C (12°F) at night and reaching a daytime maximum of 22°C (72°F), resulting in an average of 10°C (51°F). Although March has slightly less precipitation at 94 mm (3.7 in), it maintains a higher humidity level of 69% over 10 days. For a more detailed look at March conditions, you can check Castel Gandolfo weather in March.

When comparing the weather in September and April, notable differences emerge in temperature and precipitation patterns. September enjoys warmer averages, with minimums around 8°C (47°F) and highs reaching up to 32°C (90°F), while April starts off cooler, with temperatures ranging from a chilly 0°C (33°F) to a pleasant maximum of 27°C (80°F). Precipitation is higher in September, totaling 106 mm (4.2 in) over about 10 days, compared to 75 mm (2.9 in) across 11 days in April. Humidity levels also vary slightly, being 65% in September against 70% in April. For a closer look at April weather specifics, check out Castel Gandolfo weather in April.

In comparing the weather between September and May, we see notable differences in temperature and precipitation. September generally offers warmer conditions, with average temperatures around 21°C (70°F), peaking at 32°C (90°F). In contrast, May has a slightly cooler average of 18°C (64°F), though it can also reach high temperatures of 33°C (92°F). Rainfall is somewhat more frequent in September, with 106 mm (4.2 in) spread over about 10 days, while May sees an average of 89 mm (3.5 in) over 12 days, indicating that both months experience a fair amount of rain, but September tends to be wetter. Additionally, September has a humidity level of 65%, compared to May's 70%, creating a slightly more humid feel during the latter month. For more specific details about May weather, you can check the following link: Castel Gandolfo weather in May.

September and June present distinct weather patterns, reflecting the transition from summer to autumn. In September, temperatures range from a minimum of 8°C (47°F) to a maximum of 32°C (90°F), with an average of 21°C (70°F). This month experiences higher precipitation levels, totaling 106 mm (4.2 in) over about 10 days and a humidity level of 65%. In contrast, June offers milder conditions with minimum temperatures around 10°C (50°F) and maximums reaching 34°C (94°F), averaging 22°C (72°F). Rainfall is less frequent in June, accumulating only 47 mm (1.9 in) over about 7 days, accompanied by slightly lower humidity at 61%. For a more detailed look at June in particular, visit Castel Gandolfo weather in June.

When comparing the weather in July and September, notable differences emerge. July is characterized by warmer temperatures, with averages around 25°C (78°F) and highs reaching up to 36°C (96°F). In contrast, September sees a cooler average of 21°C (70°F), with maximum temperatures peaking at 32°C (90°F). Additionally, July experiences significantly less precipitation, averaging only 31 mm (1.2 in) over about 4 days, compared to September’s 106 mm (4.2 in) over 10 days. Humidity levels are also higher in September at 65%, while July maintains a lower humidity of 57%. For a closer look at July weather specifics, you can visit Castel Gandolfo weather in July.

September weather experiences cooler temperatures compared to August, with a minimum of 8°C (47°F) and an average of 21°C (70°F), while August boasts warmer nights with a minimum of 15°C (59°F) and an average of 26°C (79°F). The maximum temperatures in September peak at 32°C (90°F), which is notably lower than August's high of 37°C (99°F). Additionally, September sees significantly more precipitation, totaling 106 mm (4.2 in) over about 10 days, compared to the much drier August, which experiences only 28 mm (1.1 in) across 7 days. Humidity levels are also higher in September at 65%, juxtaposed with August's 53%. For more detailed insights about August weather, check out Castel Gandolfo weather in August.

September and October showcase notable differences in weather as summer transitions into fall. In September, temperatures can range from a mild 8°C (47°F) at night to a warm 32°C (90°F) during the day, with an average of 21°C (70°F). The month experiences a total precipitation of 106 mm (4.2 in) spread over about 10 days, and humidity sits at a comfortable 65%.

Contrastingly, October sees cooler conditions, with minimum temperatures dropping to 6°C (44°F) and an average high of 28°C (83°F), resulting in an average temperature of 16°C (62°F). While the overall precipitation remains the same at 106 mm (4.2 in) over 10 days, humidity increases to 75%, giving October a noticeably damp and crisp feel. For a more detailed look at October's climate, visit Castel Gandolfo weather in October.

September and November present a stark contrast in weather conditions. September enjoys relatively warmer temperatures, ranging from a minimum of 8°C (47°F) to a maximum of 32°C (90°F), with an average of 21°C (70°F). This month also sees about 106 mm (4.2 in) of precipitation over approximately 10 days, coupled with a humidity level of 65%. In contrast, November brings a noticeable drop in temperature, with lows plunging to -1°C (31°F) and highs reaching only 23°C (73°F), averaging around 13°C (55°F). The month is wetter, with total precipitation increasing to 191 mm (7.5 in) across 16 days, and humidity levels rising to 81%. For a closer look at what to expect, check out Castel Gandolfo weather in November.

September and December present strikingly different weather conditions. In September, temperatures range from a minimum of 8°C (47°F) to an average of 21°C (70°F), peaking at a warm 32°C (90°F). This month experiences moderate precipitation at 106 mm (4.2 in) over approximately 10 days, and humidity stands at 65%, creating a generally comfortable atmosphere. In contrast, December sees a significant drop in temperatures, with a minimum of -3°C (28°F) and an average of 8°C (47°F), reaching a maximum of only 18°C (64°F). Precipitation increases to 170 mm (6.7 in) spread across about 13 days, accompanied by higher humidity at 84%. For a more detailed look into December weather, you can refer to this link: Castel Gandolfo weather in December.

Compare Castel Gandolfo's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Castel Gandolfo

As September unfolds in Castel Gandolfo, visitors can expect a delightful transition from the summer heat to a more temperate climate. With maximum temperatures reaching around 32°C (90°F), the warm days offer plenty of sunshine, while the evenings cool down, presenting a refreshing escape with averages hovering around 21°C (70°F). This month is marked by an increase in rainfall, resulting in about 106 mm over approximately 10 days, which adds a touch of greenery to the picturesque surroundings. Additionally, the humidity sits at a comfortable 65%, striking a balance that feels pleasant rather than oppressive. Overall, September serves as a beautiful bridge between the lingering warmth of summer and the mildness of autumn. For more insights, explore the complete overview at Castel Gandolfo Climate.