September Weather in Santarem, Portugal

Last updated: February 24, 2025

In September, Santarem, Portugal, experiences a delightful blend of warm temperatures and occasional rain. With a maximum soaring to 37°C (98°F) and an average of 21°C (71°F), visitors can enjoy sunny days filled with outdoor activities. The nights bring a refreshing drop to a minimum of 11°C (51°F), perfect for a cozy evening. Although precipitation is limited, totaling 27 mm (1.1 in) over just 3 days, the humidity remains at a comfortable 67%, enhancing the scenic beauty of this historical city. Whether soaking in the sun or wandering through its charming streets, September in Santarem offers a unique and inviting atmosphere for travelers.

September Temperature in Santarem

In September, Santarem, Portugal, showcases a delightful shift towards milder temperatures as summer begins to wane. The month kicks off with minimums around 11°C (51°F), while the daily average hovers at a comfortable 21°C (71°F), making it an ideal time for outdoor explorations. With highs reaching up to 37°C (98°F), the warmth can still pack a punch; however, it signifies a slight cooling trend compared to the peak summer months of July and August, where temperatures soared to 40°C (104°F) and above. As natural landscapes begin their transition, visitors can enjoy the perks of longer days filled with pleasant weather, setting the stage for a memorable early autumn experience in this charming Portuguese town.

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

The chart illustrates September temperature patterns in Santarem, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec495456596568717270655653
Data source: Temperature data for Santarem 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 Santarem

September in Santarem, Portugal, marks a subtle transition in the weather as summer gives way to the autumn months. With 27 mm (1.1 in) of rainfall spread across just 3 days, it stands as a time of relatively low precipitation compared to the heavier showers of the months that follow. This gradual increase in moisture sets the stage for the wetter October and November, which see amounts rise significantly to 55 mm (2.2 in) and 89 mm (3.5 in), respectively. Interestingly, September's precipitation reflects a pattern of diminishing summer dryness, evident from the mere 6 mm (0.2 in) in August, emphasizing a shift towards a more humid climate as the region prepares for the cooler, rainier days ahead.

September Precipitation Trends in Santarem

The chart displays monthly precipitation patterns in Santarem, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3854808641154627568959
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Santarem

As summer gives way to autumn, September in Santarem, Portugal, sees a noticeable shift in humidity levels. Following the drier months of July and August, which maintain a consistent 60% humidity, September experiences a moderate increase to 67%. This gradual rise reflects the transition from the warmth of summer to the cooler, more refreshing breezes of fall. The humidity then continues to climb through October, reaching 74%, before peaking again in late autumn and winter months. This trend highlights a dynamic climate, where the dry summer air gives way to the more humid conditions typical of the approaching rainy season, creating a pleasant balance for both residents and visitors.

September Average Humidity in Santarem

This chart illustrates the average monthly humidity levels in Santarem, 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%75%72%70%70%63%60%60%68%74%83%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Santarem

As September rolls into Santarem, Portugal, the UV Index remains notably high at 8, categorizing it within the very high exposure range and allowing for just 15 minutes before skin damage can occur. This trend reflects a gradual decline from the peak summer months; June hit an extreme UV Index of 11, while July and August remained very high. The lingering intensity in September suggests a strong influence of residual summer sun, so it's crucial to maintain sun safety precautions even as temperatures begin to cool. For a comprehensive guide on maintaining skin health during this time, check out Santarem UV Index.

Maximum UV Index Levels in Santarem for September

The chart shows the monthly maximum UV Index (UVI) for Santarem 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.
JanFebMarAprMayJunJulAugSepOctNovDec356910111098643
Data source: Santarem 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 Santarem

In September, Santarem, Portugal, enjoys a delightful retreat into the golden embrace of autumn with approximately 347 hours of sunshine. This month marks a gentle transition from the sun-drenched days of summer, where July peaks at an impressive 420 hours. As August gives way to September, the sunlight begins to taper but still offers ample warm days to savor. Following September, the hours of sunshine continue to decline into the cooler months of October and November, showcasing how the allure of sunshine dwindles as winter approaches. Overall, September serves as a beautiful bridge, allowing residents and visitors alike to relish the lingering warmth before the crispness of autumn fully sets in.

Monthly Sunshine Duration in Santarem: September Highlighted

The September sunshine duration represents the total number of hours Santarem 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.
JanFebMarAprMayJunJulAugSepOctNovDec178h219h297h347h407h406h420h395h347h310h224h210h
Data source: Santarem September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Santarem During September

In September, Santarem, Portugal, enjoys a 55% chance of sunny weather, marking a transition into the mild autumn season. This follows the sun-drenched summer months of July and August, which boast impressive chances of 74% and 75%, respectively. While September's likelihood of sunshine is lower than the peak summer months, it still offers a substantial chance of clear skies. Compared to earlier months like February and April, which linger below the 60% mark, September presents a promising window for outdoor activities amidst the backdrop of warming fall hues. With October and November bringing a mix of sun and clouds, September stands out as a delightful time to experience Santarem's charm under the sun.

Percentage of Sunny Days in September in Santarem

The chart illustrates the percentage of sunny days in Santarem 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 Santarem experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%20%59%33%53%64%74%75%55%53%67%39%
Data source: Santarem September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Santarem in September

As September unfolds in Santarem, Portugal, the daylight duration begins its gentle decline, offering around 12 hours of sunlight each day. This gradual shift from the sun-soaked heights of summer, where daylight peaks at 14 hours in June and July, signals the approach of autumn. The transition is marked by a slight decrease, from 13 hours in August to September's 12 hours, reflecting nature's rhythm as days shorten leading into the cooler months. Notably, the steady progression of daylight through the year not only enhances the vibrancy of Santarem’s landscapes but also invites locals and visitors alike to relish the lingering warmth of early autumn before the daylight retreats further into October’s 11 hours.

Average Daylight Hours in Santarem for September

The chart illustrates the variation in daylight duration in Santarem throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 44m10h 43m11h 58m13h 15m14h 20m14h 52m14h 35m13h 37m12h 24m11h 7m10h9h 26m
Data source: Santarem daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Santarem

In September, Santarem experiences a gentle breeze with an average wind speed of 3.3 m/s (7 mph). This marks a slight decline from the warmer months of July and August, where winds picked up to around 4.1 m/s (9 mph) and 4.7 m/s (10 mph), respectively. As summer yields to autumn, the cooler air begins to move in, resulting in a more subdued wind experience. This trend of decreasing wind speeds continues into October and November, suggesting a gradual transition to the calmer breezes typical of the cooler seasons. Overall, September serves as a bridge between the lively winds of summer and the tranquil atmosphere that follows, inviting residents and visitors to enjoy the soft whispers of the approaching fall.

Average September Wind Speed in Santarem

The chart displays monthly wind speed patterns in Santarem, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.53.73.32.64.14.14.74.13.3 m/s3.13.23.9
Data source: Santarem September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Santarem Compares to Other Months

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

In September, temperatures are generally warmer, with a minimum of 11°C (51°F), an average of 21°C (71°F), and highs reaching up to 37°C (98°F), creating a more summer-like atmosphere. The month sees relatively low precipitation at 27 mm (1.1 in) over just 3 days, resulting in a moderate humidity of 67%. Conversely, January presents a stark contrast, with temperatures dropping significantly to a minimum of -3°C (26°F), an average of 10°C (50°F), and a maximum of 21°C (69°F). This winter month experiences greater precipitation at 38 mm (1.5 in) over 5 days and a notably higher humidity level at 85%. For further details on January weather, check out Santarem weather in January.

Comparing the weather between September and February reveals distinct differences in temperature and precipitation patterns. September averages a more temperate 21°C (71°F), with high temperatures reaching up to 37°C (98°F) and a moderate level of humidity at 67%. In contrast, February experiences cooler conditions, averaging just 12°C (54°F), with maximum temperatures of 25°C (77°F) and a higher humidity level of 75%. Precipitation also varies, as February typically sees more rain, with 54 mm (2.1 in) over 7 days compared to September's 27 mm (1.1 in) over only 3 days. For more detailed insights, you can refer to Santarem weather in February.

In comparing the weather of September and March, there is a notable contrast in temperature and precipitation. September offers a warmer climate, with average temperatures reaching 21°C (71°F) and maximums soaring up to 37°C (98°F), while March is cooler, averaging just 13°C (56°F), with maximums of 28°C (82°F). Humidity levels are somewhat similar, with September at 67% and March slightly higher at 72%. Regarding precipitation, March is notably wetter, receiving 80 mm (3.1 in) over about 8 days, compared to September's lighter rainfall of 27 mm (1.1 in) over just 3 days. For more details, you can check out Santarem weather in March.

In comparing the weather of September and April, several key differences emerge. September enjoys warmer temperatures, with an average of 21°C (71°F) and highs reaching up to 37°C (98°F). In contrast, April has a cooler average temperature of 15°C (59°F), with maximums around 30°C (86°F). While September experiences relatively low precipitation of 27 mm (1.1 in) over just three days, April is significantly wetter, receiving 86 mm (3.4 in) across 11 days. Humidity levels are comparable, with September at 67% and April slightly higher at 70%. For a closer look at April's conditions, you can check Santarem weather in April.

In September, the weather tends to be warmer, with average temperatures reaching 21°C (71°F) and maximums climbing up to 37°C (98°F), while May is cooler, with an average of 18°C (65°F) and highs close to 36°C (96°F). Precipitation is lower in September at 27 mm (1.1 in) over about 3 days, compared to May's 41 mm (1.6 in) spread over 5 days. Humidity remains relatively similar, with September at 67% and May at 70%. For more specifics on May weather, check out Santarem weather in May.

September and June exhibit somewhat similar temperature ranges, with September averaging 21°C (71°F) and June slightly cooler at 20°C (68°F). However, June tends to have more extreme high temperatures, peaking at 41°C (106°F) compared to September's maximum of 37°C (98°F). In terms of precipitation, September experiences more rainfall with a total of 27 mm (1.1 in) over 3 days, while June has only 15 mm (0.6 in) across 4 days of rain. Additionally, September's humidity is slightly higher at 67%, compared to June's 63%. For a closer look at June weather conditions, you can check Santarem weather in June.

In comparing the weather of September and July, we see notable differences in temperature and precipitation patterns. September experiences a more moderate temperature range with a minimum of 11°C (51°F) and a maximum of 37°C (98°F), averaging around 21°C (71°F). In contrast, July tends to be hotter, with a minimum of 13°C (56°F), an average of 22°C (72°F), and a maximum reaching up to 40°C (104°F). Additionally, July is considerably drier, receiving only 3 mm (0.1 in) of precipitation over just one day, while September sees slightly increased rainfall, with 27 mm (1.1 in) on three days. The humidity is also higher in September at 67% compared to July’s 60%. For a more detailed look at July weather, you can visit Santarem weather in July.

September weather shows a slight decrease in minimum temperatures compared to August, with lows of 11°C (51°F) versus August's 13°C (56°F). The average temperatures are comparable, but September experiences a more moderate maximum temperature of 37°C (98°F) compared to the sweltering highs of 43°C (110°F) seen in August. In terms of precipitation, September has a higher total of 27 mm (1.1 in) over 3 days, while August remains quite dry with only 6 mm (0.2 in) over 1 day. Humidity is also slightly higher in September at 67%, compared to 60% in August. For a detailed overview of August's weather, you can refer to Santarem weather in August.

September weather tends to be warmer, with average temperatures around 21°C (71°F) and maximums reaching up to 37°C (98°F). It features relatively low precipitation levels at 27 mm (1.1 in) over just three days, along with a humidity level of 67%. In contrast, October experiences cooler temperatures, with an average of 18°C (65°F) and a minimum dropping to 6°C (44°F). This month also sees increased precipitation, totaling 55 mm (2.2 in) over five days, alongside a rise in humidity to 74%. For more detailed information, you can visit Santarem weather in October.

In September, the weather offers a warm mix with average temperatures around 21°C (71°F) and maximum highs reaching up to 37°C (98°F), accompanied by relatively low precipitation of 27 mm (1.1 in) over just three days. However, as November rolls in, temperatures drop significantly, with averages settling at 13°C (56°F) and maximums peaking at 25°C (78°F). November also brings increased rainfall, with 89 mm (3.5 in) falling across ten days, resulting in a much higher humidity level of 83%. For a detailed overview of what to expect, you can check Santarem weather in November.

September and December present strikingly different weather conditions. In September, temperatures range from a pleasant 11°C (51°F) at night to a scorching 37°C (98°F) during the day, with an average of 21°C (71°F). This month experiences relatively low precipitation, with only 27 mm (1.1 in) over about three days and humidity levels at 67%. In contrast, December sees much cooler temperatures, with a minimum of -2°C (28°F), an average of 11°C (53°F), and a maximum of 20°C (68°F). Precipitation increases significantly to 59 mm (2.3 in) across eight days, contributing to higher humidity levels at 85%. For more detailed insights, you can check out Santarem weather in December.

Compare Santarem's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Santarem

As September rolls in, Santarem experiences a delightful transition from the sweltering summer heat to a milder climate, making it a charming month to explore. The combination of a maximum temperature reaching up to 37°C and an average of 21°C showcases the lingering warmth, yet the evenings often bring a refreshing coolness, with temperatures dipping to a pleasant 11°C. Unlike the heavier downpours of the rainy season, September's 27 mm of rainfall over just 3 days contributes to a more comfortable humidity level of 67%, making outdoor activities enjoyable. This month serves as a beautiful bridge to the fall, offering a unique weather experience distinct from the more intense heat of the preceding summer months. To learn more about seasonal variations and how Santarem's climate shapes your visit, check out Santarem Climate.