September Weather in San Marino, Italy

Last updated: March 24, 2025

September in San Marino offers a delightful mix of late summer warmth and early autumn charm. With maximum temperatures reaching an inviting 34°C (94°F) and an average of 21°C (70°F), visitors can still enjoy plenty of sunshine. However, the month also brings a refreshing shift, as minimum temperatures can drop to a brisk 7°C (45°F), perfect for cozy evenings. Expect some rainfall with 84 mm (3.3 in) over approximately 10 days, contributing to the region's lush scenery. The humidity averages around 66%, adding to the comfortable yet refreshing atmosphere, making September a wonderful time to explore this picturesque locale.

September Temperature in San Marino

In September, San Marino experiences a gentle transition from the sweltering summer days to the cooler embrace of autumn. With minimum temperatures averaging around 7°C (45°F) and reaching pleasant highs of 34°C (94°F), this month provides a delightful mix of warmth and coolness. The average temperature settles at a comfortable 21°C (70°F), making it an ideal time for outdoor explorations and festivities. Compared to the scorching peaks of August, when temperatures soared to 41°C (106°F), September offers a refreshing respite, inviting visitors to bask in the vibrant autumn foliage while enjoying the mild yet pleasant climate. This harmonious blend of warmth and cooling breezes creates a captivating atmosphere, perfect for savoring the beauty of this historic region.

September Weather in San Marino: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in San Marino, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec394550576676798070605142
Data source: Temperature data for San Marino 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 San Marino

September in San Marino marks a notable shift in the weather pattern, bringing 84 mm (3.3 in) of precipitation over 10 days. This increase reflects a transition from the drier summer months, where August saw only 48 mm (1.9 in), to a more autumnal climate as the year progresses. The rise in rainfall not only enhances the lush landscape but also sets the stage for the wetter months ahead, with precipitation peaking in November at 109 mm (4.3 in). As September fades into October, residents can expect a balance of sun and showers, with October's average rainfall dropping to 61 mm (2.4 in) over 8 days, signaling a gradual easing back into the milder, rainier season.

September Precipitation Trends in San Marino

The chart displays monthly precipitation patterns in San Marino, 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.
JanFebMarAprMayJunJulAugSepOctNovDec23734655100446848846210967
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in San Marino

As summer gradually gives way to autumn, September in San Marino experiences a notable shift in humidity, settling at 66%. This marks a slight uptick from the notably dry months of July and August, where humidity dipped to a comfortable 61% and 54%, respectively. While September's figures signify a return to more humid conditions, they still remain remarkably lower than the peak levels seen in the colder months, like January's 87% or November's staggering 88%. This transitional month serves as a reminder of the changing seasons, where the air becomes crisper, yet the remains of summer linger, providing a pleasant balance before the arrival of the wetter, cooler autumn days.

September Average Humidity in San Marino

This chart illustrates the average monthly humidity levels in San Marino, 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.
JanFebMarAprMayJunJulAugSepOctNovDec87%79%69%71%70%65%61%54%66%83%88%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in San Marino

As September arrives in San Marino, the UV Index remains a robust 7, indicating a high level of sun exposure that demands caution. This month's index shows a notable drop from the peak summer values of 9 in July and June, yet it still requires vigilance, especially as the burn time decreases to 25 minutes. With outdoor activities on the rise during the pleasant early autumn days, it's essential to embrace sun safety measures. The overall trend from the height of summer to early fall reflects a gradual easing of intensity, making it a prime time to enjoy the beauty of San Marino while remaining sun-smart. For detailed information, check out the San Marino UV Index.

Maximum UV Index Levels in San Marino for September

The chart shows the monthly maximum UV Index (UVI) for San Marino 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.
JanFebMarAprMayJunJulAugSepOctNovDec235789987532
Data source: San Marino 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 San Marino

September in San Marino showcases a delightful transition from the sweltering summer months, as the city basks in 338 hours of sunshine. This is a notable decrease from the peak of 428 hours in July, yet it still offers an abundance of bright days perfect for outdoor exploration. The sunshine gently wanes into autumn, following a consistent trend of declining daylight, with October bringing 301 hours of sunlight. This gradual reduction, however, highlights the beauty of September, where the warmth lingers just enough to enjoy the picturesque landscapes and charming streets before the cooler months settle in.

Monthly Sunshine Duration in San Marino: September Highlighted

The September sunshine duration represents the total number of hours San Marino 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.
JanFebMarAprMayJunJulAugSepOctNovDec181h224h313h346h389h421h428h398h338h301h220h218h
Data source: San Marino September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in San Marino During September

September in San Marino enjoys a moderate chance of sunshine, with approximately 55% of days likely to be sunny. This marks a slight dip from the summer months, where July and August bask in even brighter conditions with chances peaking at 54% and 62% respectively. As the year transitions into autumn, September still offers a pleasant opportunity for outdoor activities, standing out as a balanced month between the sizzling summer and the cooler fall. This transitional period presents a compelling allure for visitors seeking to enjoy the remaining warmth before winter settles in, making it a delightful time to explore the scenic landscapes and historic charm of San Marino.

Percentage of Sunny Days in September in San Marino

The chart illustrates the percentage of sunny days in San Marino 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 San Marino experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec38%44%69%47%49%61%54%62%55%45%29%44%
Data source: San Marino September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in San Marino in September

As summer fades into autumn, September in San Marino brings a gentle transition with approximately 12 hours of daylight. This marks a gradual decline from the peak of 15 hours in June and July, reflecting nature's rhythm as days steadily shorten. The month begins with lingering warmth, allowing for ample time to enjoy the stunning landscapes and historical sites bathed in soft, golden light. With daylight diminishing from August’s 13 hours, September signals a shift towards 10 hours in October, inviting residents and visitors alike to embrace the cooler, crisper days ahead, while still relishing the beauty of early autumn.

Average Daylight Hours in San Marino for September

The chart illustrates the variation in daylight duration in San Marino throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 15m10h 26m11h 56m13h 29m14h 48m15h 28m15h 7m13h 57m12h 28m10h 56m9h 35m8h 52m
Data source: San Marino daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in San Marino

As September unfolds in San Marino, Italy, a subtle shift in the breeze is noticeable, with average wind speeds dipping to 1.8 m/s (4 mph). This marks a continuation of a trend observed throughout the summer, where wind speed remained relatively low, hovering around 2.1 to 2.9 m/s. The gentle hands of autumn begin to caress the landscape, contrasting with the slightly stronger winds of late spring, which peaked in May. As the month advances, the air feels softer, embracing the beautiful interplay of warm days and cooler nights. While wind speeds begin to rise gently again in October, September’s calm is a soothing prelude to the more dynamic changes that the autumn months promise.

Average September Wind Speed in San Marino

The chart displays monthly wind speed patterns in San Marino, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.22.12.22.42.92.22.12.41.8 m/s2.32.21.7
Data source: San Marino September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in San Marino Compares to Other Months

The weather in San Marino 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 San Marino and find detailed weather information for every month.

September and January offer strikingly different weather conditions. In September, the temperatures are warm, ranging from a minimum of 7°C (45°F) to a maximum of 34°C (94°F), with an average temperature of 21°C (70°F). The month also sees moderate precipitation of 84 mm (3.3 in) over about 10 days, accompanied by a humidity level of 66%. In contrast, January experiences much colder conditions, with temperatures plummeting to a minimum of -6°C (21°F) and reaching a maximum of 15°C (60°F). The average temperature is just 4°C (40°F), and precipitation is significantly lower at 23 mm (0.9 in) over 4 days, alongside a higher humidity of 87%. For more details on January weather specifically, you can visit San Marino weather in January.

September and February present contrasting weather conditions. In September, temperatures range from a mild 7°C (45°F) at night to a warm 34°C (94°F) during the day, with an average of 21°C (70°F). This month experiences more rainfall, totaling 84 mm (3.3 in) over approximately 10 days, accompanied by a humidity level of 66%. In contrast, February is significantly colder, with temperatures dipping as low as -9°C (16°F) at night and reaching a maximum of 21°C (70°F) during the day, resulting in an average of only 7°C (45°F). Although February sees slightly less precipitation at 73 mm (2.9 in) over 9 days, the humidity increases to 79%. For more detailed insights, check out San Marino weather in February.

September and March exhibit contrasting weather patterns that reflect the transition between summer and winter. In September, temperatures range from a mild 7°C (45°F) at night to a warm 34°C (94°F) during the day, with an average of 21°C (70°F). The month also sees a fair amount of rainfall, with 84 mm (3.3 in) spread over about 10 days, coupled with a humidity level of 66%. In contrast, March experiences a cooler climate, with minimum temperatures dropping to -11°C (12°F) and a maximum of 25°C (77°F), averaging around 10°C (50°F). Precipitation is less frequent, totaling 46 mm (1.8 in) over 7 days, while humidity slightly increases to 69%. For more detailed insights into the weather during this month, check out San Marino weather in March.

September and April present contrasting weather conditions. In September, temperatures range significantly from a cool 7°C (45°F) at night to a warm 34°C (94°F) during the day, with an average of 21°C (70°F). The month experiences about 84 mm (3.3 in) of rainfall spread over 10 days, with a humidity level of 66%. In contrast, April features cooler temperatures, ranging from a chilly -1°C (30°F) at night to a maximum of 28°C (82°F) during the day, averaging around 14°C (58°F). Precipitation is lighter in April, totaling about 55 mm (2.2 in) over 8 days, with a slightly higher humidity level of 71%. For those interested in more details, you can check out San Marino weather in April.

September and May present contrasting weather patterns, though both months feature pleasant temperatures. In September, the average temperature sits at 21°C (70°F), rising to a maximum of 34°C (94°F), with minimum temperatures of 7°C (45°F). On the other hand, May offers slightly cooler conditions, with an average of 19°C (66°F) and a maximum of 33°C (91°F), while the minimum is just a degree lower at 6°C (44°F). Precipitation also differs between these months, as September receives about 84 mm (3.3 in) over 10 days, compared to May's 100 mm (3.9 in) over 14 days. The humidity levels are relatively similar, with September at 66% and May slightly higher at 70%. For more detailed insights, check San Marino weather in May.

In comparing the weather of September and June, September tends to have a wider range of temperatures, with nighttime lows dropping to around 7°C (45°F) and daytime highs reaching up to 34°C (94°F). The average temperature in September is about 21°C (70°F) with higher rainfall, totaling 84 mm (3.3 inches) over approximately 10 days, and humidity sitting at 66%. In contrast, June offers warmer nights with a minimum of 12°C (54°F) and hotter days reaching up to 40°C (104°F), averaging around 25°C (76°F). Precipitation is less in June, amounting to 43 mm (1.7 inches) over about 7 days, while humidity remains slightly lower at 65%. For more detailed insights, you can check San Marino weather in June.

September weather shows a significant drop in minimum temperatures compared to July, with lows of 7°C (45°F) versus July's 16°C (61°F). The average temperature in September is milder at 21°C (70°F), while July remains warmer at an average of 26°C (80°F). Despite September experiencing slightly more precipitation at 84 mm (3.3 in) over 10 days, July has fewer rainy days, totaling 68 mm (2.7 in) across 8 days. Additionally, humidity is slightly higher in September at 66%, compared to 61% in July. For more details, check out San Marino weather in July.

In comparing the weather of September and August, September experiences a wider temperature range, with minimums of 7°C (45°F) and maximums reaching 34°C (94°F), while August has warmer temperatures, ranging from a minimum of 13°C (55°F) to a maximum of 41°C (106°F). The average temperature in September is milder at 21°C (70°F) compared to August's warmer average of 26°C (80°F). Additionally, September sees more precipitation, accumulating 84 mm (3.3 in) over 10 days, in contrast to August's 48 mm (1.9 in) over 7 days. The humidity also increases in September to 66%, compared to 54% in August, making September feel more humid despite its cooler temperatures. For more detailed information, you can check San Marino weather in August.

September typically brings warmer temperatures, with a minimum of 7°C (45°F) and an average high of 34°C (94°F), while October experiences cooler conditions, with a minimum of 5°C (41°F) and an average maximum of 28°C (82°F). Additionally, September tends to be drier, recording 84 mm (3.3 in) of precipitation over 10 days, compared to October's 61 mm (2.4 in) over 8 days. Humidity levels also rise in October to 83%, up from 66% in September, contributing to a more pronounced autumn feel. For more details, check San Marino weather in October.

September and November present quite different weather experiences. In September, temperatures are much warmer, ranging from a minimum of 7°C (45°F) to a maximum of 34°C (94°F), with an average of 21°C (70°F). This month sees moderate rainfall of 84 mm (3.3 inches) across about 10 days, accompanied by a relatively comfortable humidity level of 66%. In contrast, November ushers in cooler temperatures, with a minimum of -2°C (29°F) and a maximum of 21°C (70°F), leading to an average of just 11°C (51°F). Precipitation increases to 109 mm (4.3 inches) over 11 days, coupled with higher humidity at 88%. The transition from the warmth of September to the chill of November marks a significant shift in the climate. For more detailed insights about November weather specifically, you can check San Marino weather in November.

The weather in September is notably warmer compared to December, with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 34°C (94°F), leading to an average of 21°C (70°F). In contrast, December sees significantly lower temperatures, with a minimum of -4°C (24°F) and a maximum of 17°C (62°F), averaging 6°C (42°F). Although both months experience precipitation over roughly 10 days, September receives 84 mm (3.3 in) of rain compared to December’s 67 mm (2.7 in), which tends to come with higher humidity levels in December at 85% versus 66% in September. For a more detailed look at December conditions, check out San Marino weather in December.

Compare San Marino's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in San Marino

As September unfolds in San Marino, the weather presents a delightful transition from the intense summer heat to more moderate conditions. With an average temperature around 21°C (70°F), visitors will find the climate much more comfortable when compared to the scorching peaks of July and August. Although temperatures can still rise to a warm 34°C (94°F), cooler evenings bring a refreshing respite. This month also experiences a modest increase in precipitation, with around 84 mm distributed over approximately 10 days, adding a touch of humidity at 66%. As nature begins to shift toward autumn, September offers a unique blend of sunshine and occasional rain, making it an ideal time to explore the breathtaking landscapes of this charming microstate. For a deeper understanding of what to expect, check out San Marino Climate.