Last updated: August 21, 2025
March in Porto Alegre, Brazil brings a warm climate characterized by a maximum temperature soaring up to 38°C (100°F). On average, the city enjoys a pleasant 23°C (75°F), while nighttime temperatures can dip to a refreshing 13°C (56°F). Despite the warmth, residents experience moderate rainfall, with 109 mm (4.3 in) accumulating over 12 days, contributing to a humidity level of 79%. This combination of heat and moisture creates a vibrant, lively atmosphere, making March an intriguing month for both locals and visitors alike.
In March, Porto Alegre begins to transition away from the intense heat of summer, with temperatures averaging 23°C (75°F). The month starts off pleasantly with minimum temperatures dipping to 13°C (56°F), while daytime highs can still reach a warm 38°C (100°F). This lingering warmth reflects the tail end of the hot season, as the city experiences a gradual cooling trend leading into autumn. Notably, compared to January and February, where maximum temperatures soared up to 39°C (103°F) and 38°C (100°F) respectively, March showcases a more comfortable climate, making it an ideal time for outdoor activities while still enjoying the summer warmth. As the month progresses, residents can expect cooler evenings, setting the stage for the refreshing change of April ahead.
In March, Porto Alegre experiences a significant rainfall with an average precipitation of 109 mm (4.3 in) over 12 days, marking a slight decrease compared to the preceding month of February, which saw 112 mm (4.4 in). This trend illustrates a transitional phase as the city shifts from the wetter summer months into the milder autumn season. Notably, March’s precipitation is still robust, falling within a pattern of consistent rainfall that characterizes the city’s late summer and early autumn months. As the year progresses, April brings a notable reduction to 73 mm (2.9 in), highlighting a gradual decline in precipitation as Porto Alegre heads into the cool season.
As March settles in Porto Alegre, the city experiences a slight leveling off with humidity at 79%, maintaining the same moisture levels as February. This hints at a consistent late-summer climate, where warm temperatures gradually begin to rise alongside humidity. Notably, as the season transitions into April, there is a marked increase to 82%, foreshadowing the more humid and rainier months ahead. While March remains relatively stable, it serves as a precursor to the more humid conditions that will dominate as the year progresses, peaking in the later months like May with 87% humidity. This ebb and flow of moisture levels reflects the tropical character of Porto Alegre, creating a lush atmosphere as it heads toward winter.
In March, Porto Alegre experiences a UV Index of 12, categorized as extreme, which means sun exposure can lead to skin damage in as little as 10 minutes. This late summer trend follows the high indices of January and February, where the UV levels were also extreme, with values of 14 and 13, respectively. As the month progresses into April, there’s a noticeable decline to a UV Index of 9, shifting to a very high exposure category and allowing for slightly longer sun safe periods. This downward trend in UV levels hints at the gradual transition from the intense summer sun toward milder, autumn conditions. For those looking to understand the UV situation throughout the year, further details can be found at Porto Alegre UV Index.
UV Risk Categories
March in Porto Alegre is truly a time of vibrant sunshine, with an impressive 312 hours of bright days gracing the city. This marks a slight increase from February's 310 hours, suggesting a steady transition into the more radiant and warmer months ahead. Following March, April sees a dip to 271 hours, indicating the onset of changes as autumn approaches. The consistent hours of sunshine in the early months of the year, compared to the later months, illustrate a distinct seasonal pattern that enriches the charm of Porto Alegre. With November and December boasting the highest sunshine hours at 316 and 361 hours respectively, it's clear that the city thrives under the sun’s embrace, especially as the year swings back towards summer. Enjoying its sun-soaked days, Porto Alegre remains a haven for those seeking warmth and light in their lives.
In March, Porto Alegre experiences a 40% chance of sunny weather, making it a somewhat transitional month as summer gives way to autumn. This figure reflects a slight decline from February's brighter 59%, but it’s worth noting that sunny days tend to rebound in April with a 54% likelihood. Overall, the sunny probabilities throughout the year reveal interesting trends; after peaking in July at 60%, chances fluctuate, often dipping to their lowest in the winter months like June at 32% and September at 30%. Thus, while March offers a moderate chance of sunshine, the city's weather hints at greater possibilities as it moves deeper into autumn.
As March unfolds in Porto Alegre, Brazil, the city experiences a notable shift in daylight duration, offering about 12 hours of sunlight each day. This marks a gradual decrease from the 13 hours enjoyed in the preceding months of January and February. The trend reveals a steady reduction of daylight as autumn approaches, with April dipping to 11 hours, followed by May at 10 hours. This pattern contrasts with the longer days of the previous summer months and highlights the transition in the seasonal cycle. As nature gradually prepares for a cooler phase, residents can savor the golden hues of early autumn while embracing the shorter, yet still vibrant, daylight hours.
As March unfolds in Porto Alegre, the winds begin to soften, with average wind speeds dropping to 2.6 m/s (6 mph). This slight decline from February’s 2.9 m/s (7 mph) creates a noticeable difference in the atmosphere as the summer heat starts to wane. Interestingly, the transition to April brings a minor uptick, stabilizing at 2.7 m/s (6 mph), suggesting a gentle breeze that complements the city's early autumn charm. Observing the broader seasonal trends, following March, the winds start to pick up again, peaking in June before descending gradually towards the end of the year. Thus, March serves as a calm interlude, poised between the lingering warmth of summer and the crispness of fall that lies ahead.
Weather in Porto Alegre varies notably across the year, with each month offering distinct climate conditions. This page compares March’s weather to other months in Porto Alegre, focusing on differences in temperature, rainfall, humidity, and UV levels.
When comparing the weather in March to that of January, we see some notable differences. In March, the minimum temperature is slightly lower at 13°C (56°F), while the average temperature drops to 23°C (75°F). In contrast, January boasts a higher minimum temperature of 15°C (58°F) and a warmer average of 26°C (79°F). Both months feature similar maximum temperatures, with March reaching up to 38°C (100°F), while January peaks at a slightly higher 39°C (103°F). Rainfall is more abundant in March, with 109 mm (4.3 in) over 12 days, compared to January's 93 mm (3.7 in) over the same number of days. Humidity levels are also comparable, with March recording 79% and January at 77%. For more detailed insights, you can check Porto Alegre weather in January.
In comparing the weather between February and March, both months experience quite similar temperature ranges, with March seeing a minimum temperature of 13°C (56°F) and an average of 23°C (75°F), while February has a slightly higher minimum of 14°C (58°F) and an average of 25°C (77°F). Both months can reach a maximum of 38°C (100°F), but February has marginally more precipitation at 112 mm (4.4 in) compared to March's 109 mm (4.3 in), with February also having a day less of precipitation at 11 days compared to March's 12 days. Humidity levels remain constant at 79% for both months, indicating a consistently humid environment. For more details on February weather, you can check Porto Alegre weather in February.
March and April exhibit notable differences in weather patterns. In March, temperatures are generally warmer, with a minimum of 13°C (56°F) and an average high reaching up to 38°C (100°F). The month is characterized by significant rainfall, accumulating to 109 mm (4.3 in) over about 12 days, coupled with a humidity level of 79%. In contrast, April brings cooler temperatures, featuring a minimum of 8°C (47°F) and a maximum of 34°C (93°F), while the average temperature slightly decreases to 21°C (71°F). Precipitation also lessens to 73 mm (2.9 in) over just 8 days, and humidity rises slightly to 82%. For a detailed overview, you can check out the Porto Alegre weather in April.
In comparing the weather conditions of March and May, notable differences emerge in both temperature and precipitation. March experiences warmer temperatures with a minimum of 13°C (56°F) and an average of 23°C (75°F), peaking at a scorching 38°C (100°F). In contrast, May presents a cooler climate, where temperatures dip to a minimum of 5°C (41°F), an average of 17°C (63°F), and a maximum of 32°C (90°F). Additionally, while March sees 109 mm (4.3 in) of precipitation over 12 days, May receives even higher rainfall at 153 mm (6.0 in) despite having precipitation on just 10 days. The humidity also increases slightly from March's 79% to May's 87%, contributing to a more damp environment. For further details on May's weather in Porto Alegre, you can check Porto Alegre weather in May.
When comparing the weather in March and June, notable differences emerge in temperature and humidity. March boasts warmer temperatures, with a minimum of 13°C (56°F), an average of 23°C (75°F), and a maximum reaching 38°C (100°F). In contrast, June presents cooler temperatures, starting at a minimum of just 3°C (38°F) and averaging 16°C (60°F), with a maximum of 31°C (88°F). Both months experience significant precipitation, with March receiving 109 mm (4.3 in) over 12 days and June slightly higher at 113 mm (4.4 in) over 9 days. Humidity levels are also greater in June at 85%, compared to March's 79%. For more detailed weather insights, you can check Porto Alegre weather in June.
March and July exhibit stark differences in weather patterns. In March, temperatures range from a mild 13°C (56°F) to a scorching max of 38°C (100°F), with an average of 23°C (75°F). The month sees considerable rainfall, with 109 mm (4.3 in) of precipitation over 12 days, accompanied by high humidity at 79%. In contrast, July presents a cooler climate, with temperatures peaking at a maximum of 30°C (87°F) and dropping to a minimum of 2°C (35°F), resulting in an average of only 14°C (58°F). However, precipitation is slightly higher at 122 mm (4.8 in), spread over just 8 days, with humidity remaining elevated at 82%. For more details, you can check Porto Alegre weather in July.
The weather in March is notably warmer compared to August, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 38°C (100°F) and an average of 23°C (75°F). It experiences a higher level of precipitation, totaling 109 mm (4.3 in) over about 12 days, combined with a humidity level of 79%. In contrast, August features cooler temperatures, with a minimum of 3°C (38°F) and a maximum of 34°C (94°F), averaging around 16°C (61°F). This month sees less rainfall, with 70 mm (2.8 in) over 8 days and a slightly higher humidity of 81%. For more details, you can check Porto Alegre weather in August.
In March, Porto Alegre experiences warmer temperatures, with a minimum of 13°C (56°F) and an average of 23°C (75°F), peaking at a scorching 38°C (100°F). The month also sees significant rainfall, totaling 109 mm (4.3 in) over 12 days, and a humidity level of 79%. In contrast, September temperatures dip noticeably, starting with a minimum of 7°C (45°F) and averaging 18°C (65°F), while max temperatures reach 36°C (96°F). Rainfall increases in September, measuring 155 mm (6.1 in) across the same number of rainy days, with humidity slightly higher at 84%. For more detailed information, you can check Porto Alegre weather in September.
In March, temperatures in Porto Alegre range from a minimum of 13°C (56°F) to a maximum of 38°C (100°F), with an average of 23°C (75°F). The month experiences about 109 mm (4.3 inches) of precipitation over 12 days, and humidity hovers around 79%. In contrast, October sees cooler temperatures, with a minimum of 9°C (49°F) and an average of 20°C (68°F), while still reaching a maximum of 37°C (100°F). Precipitation increases slightly to 139 mm (5.5 inches) over 13 days, and humidity rises to 85%. For more details, you can check Porto Alegre weather in October.
March and November in Porto Alegre present similar temperatures and weather patterns, yet notable differences remain. In March, temperatures range from a minimum of 13°C (56°F) to a maximum of 38°C (100°F), with an average of 23°C (75°F). The month experiences about 109 mm (4.3 in) of precipitation over 12 days and a humidity level of 79%. In contrast, November sees slightly lower temperatures, with a minimum of 12°C (53°F) and a maximum of 37°C (99°F), averaging 22°C (72°F). This month has comparable precipitation levels at 112 mm (4.4 in), but fewer rainy days at just 10, along with a slightly higher humidity of 82%. For more details, you can check Porto Alegre weather in November.
In March, temperatures in Porto Alegre range from a minimum of 13°C (56°F) to a maximum of 38°C (100°F), with an average of 23°C (75°F). This month also sees more precipitation, totaling 109 mm (4.3 in) over about 12 days, contributing to a humidity level of 79%. In contrast, December features slightly milder temperatures, with a minimum of 13°C (55°F), an average of 24°C (76°F), and a slightly higher maximum of 38°C (101°F). Rainfall in December is less frequent, amounting to 80 mm (3.2 in) over 8 days, resulting in a higher humidity of 84%. For a more detailed look at weather specifics, check out Porto Alegre weather in December.
In March, Porto Alegre experiences a distinct shift in weather, characterized by warmer temperatures and increased humidity as the summer draws to a close. Compared to other months, the city can reach its maximum highs of 38°C, providing a tropical feel, while the average temperature settles comfortably at 23°C. However, with about 12 days of rainfall adding up to 109 mm, the air tends to be more humid at 79%, making for a muggy atmosphere that can differ markedly from the drier, cooler conditions of the winter months. This transitional period showcases the vibrant climate of the region, perfect for outdoor exploration before the cooler weather sets in. For a more detailed look at weather patterns throughout the year, check out Porto Alegre Climate.