Climate in Porto Alegre (Rio Grande do Sul)

The climate of Porto Alegre is subtropical, with very mild winters (from May to August) and hot summers (from December to March). The weather is very variable, and the rains are abundant and quite frequent all year round, with a maximum in winter (unlike what happens in north-central Brazil).
The city is located in southern Brazil, in the state of Rio Grande do Sul (of which it is the capital), at 30 degrees south latitude. The coast of the Atlantic Ocean is 95 km (60 mi) to the east, but the city overlooks Lake Guaíba, also known as River Guaíba, where five different rivers converge. To the south, the lake widens into the Lagoa dos Patos, a large lagoon parallel to the coast that reaches the cities of Pelotas and Rio Grande.
In winter, from May to August (but sometimes also in September), there can be cold waves from the south, during which the temperature can drop to the freezing point at night, and can remain around 10/12 °C (50/54 °F) during the day.
Sometimes it can even snow. In August 1984, there was a light snowfall with accumulation.
In autumn and winter, fog can form at night and in the early morning.
In summer, on the other hand, there can be heat waves.

Best Time

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There is no perfect time to visit Porto Alegre. From May to August, temperatures are normally mild, however, it can get cold at times. You can then choose the period from mid-April to mid-May, in which temperatures are intermediate between winter and summer.
For a beach holiday it will be necessary to choose the summer, from January to March, even though the air is often hot and humid, there can be severe thunderstorms and sometimes even heat waves.

Porto Alegre - Climate data

In Porto Alegre, the average temperature of the coldest month (July) is of 15.1 °C (59.2 °F), that of the warmest month (January) is of 25.9 °C (78.6 °F). Here are the average temperatures.
Precipitation amounts to 1425 millimeters (56.1 inches) per year: it is therefore quite abundant. It ranges from 90 mm (3.5 in) in the driest month (March) to 140 mm (5.5 in) in the wettest ones (June, July, September, October) Here is the average precipitation.
The sea temperature ranges from 16 °C (61 °F) in August to
There are on average around 2105 sunshine hours per year. Here are the average hours of sunshine per day.

Porto Alegre - Weather by month

Based on the period 1991-2020

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January, the hottest month of the year, is generally a warm to hot, muggy month. The average temperature is of 25.9 °C (79 °F), with a minimum of 20.6 °C (69.2 °F) and a maximum of 31.1 °C (88.1 °F).
On the coldest nights of the month, the temperature usually drops to around 15.5 °C (60 °F). However, it dropped to 10.6 °C (51.1 °F) in January 1998.
On the warmest days of the month, the temperature usually reaches around 36 °C (97 °F). However, it reached 39 °C (102.2 °F) in January 2006.
Precipitation amounts to 110 mm (4.3 in), distributed over 9 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 53% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).
The average sea temperature is of 24.5 °C (76 °F). Therefore, the sea is warm enough for swimming.

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February is generally a warm to hot, muggy month. The average temperature is of 25.9 °C (79 °F), with a minimum of 20.9 °C (69.6 °F) and a maximum of 30.9 °C (87.5 °F).
On the coldest nights of the month, the temperature usually drops to around 15.5 °C (60.5 °F). However, it dropped to 9 °C (48.2 °F) in February 1991.
On the warmest days of the month, the temperature usually reaches around 36 °C (96.5 °F). However, it reached 40 °C (104 °F) in February 2014.
Precipitation amounts to 105 mm (4.1 in), distributed over 8 days.
The day lasts on average 13 hours and 5 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 53% of the time.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 25 °C (77 °F). Therefore, the sea is warm enough for swimming.

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March is generally a warm to hot, muggy month. The average temperature is of 24.6 °C (76 °F), with a minimum of 19.5 °C (67.1 °F) and a maximum of 29.7 °C (85.5 °F).
On the coldest nights, the temperature usually drops to around 13.5 °C (56.5 °F). However, it dropped to 9.4 °C (48.9 °F) in March 2000.
On the warmest days, the temperature usually reaches around 35 °C (95 °F). However, it reached 38 °C (100.4 °F) in March 2020.
Precipitation amounts to 90 mm (3.5 in), distributed over 8 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 24.5 °C (76.5 °F). Therefore, the sea is warm enough for swimming.

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April is generally a warm month. The average temperature is of 21.6 °C (71 °F), with a minimum of 16.4 °C (61.6 °F) and a maximum of 26.8 °C (80.3 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 9.5 °C (49 °F). However, it dropped to 3.8 °C (38.8 °F) in April 1991.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 33 °C (91 °F). However, it reached 37 °C (98.6 °F) in April 1996.
Precipitation amounts to 105 mm (4.1 in), distributed over 9 days.
The day lasts on average 11 hours and 20 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 23 °C (73 °F). Therefore, the sea can be considered barely acceptable for swimming.

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May is generally a very mild month. The average temperature is of 18 °C (64 °F), with a minimum of 13 °C (55.5 °F) and a maximum of 23 °C (73.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 5.5 °C (42.5 °F). However, it dropped to 0.4 °C (32.7 °F) in May 1992.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 29.5 °C (85 °F). However, it reached 33 °C (91.4 °F) in May 2002.
Precipitation amounts to 120 mm (4.7 in), distributed over 9 days.
The day lasts on average 10 hours and 35 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 45% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 9 kph (5 mph).
The average sea temperature is of 20.5 °C (68.5 °F). Therefore, the sea is cool for swimming.

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June is generally a very mild month. The average temperature is of 16 °C (61 °F), with a minimum of 10.8 °C (51.5 °F) and a maximum of 21.1 °C (69.9 °F).
On the coldest nights, the temperature usually drops to around 3.5 °C (38 °F). However, it dropped to -1 °C (30.2 °F) in June 1996.
On the warmest days, the temperature usually reaches around 29 °C (84 °F). However, it reached 32 °C (89.6 °F) in June 2006.
Precipitation amounts to 140 mm (5.5 in), distributed over 9 days.
The day lasts on average 10 hours and 10 minutes. June 21, the winter solstice, is the shortest day of the year in the Southern Hemisphere.
There are on average 4 hours of sunshine per day. So, the sun shines 38% of the time.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 18 °C (64.5 °F). Therefore, the sea is cold for swimming.

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July, the coldest month of the year, is generally a very mild month. The average temperature is of 15.1 °C (59 °F), with a minimum of 9.8 °C (49.7 °F) and a maximum of 20.4 °C (68.7 °F).
On the coldest nights of the month, the temperature usually drops to around 2 °C (35.5 °F). However, it dropped to -3.2 °C (26.2 °F) in July 1991.
On the warmest days of the month, the temperature usually reaches around 29.5 °C (85 °F). However, it reached 32.3 °C (90.1 °F) in July 2005.
Precipitation amounts to 140 mm (5.5 in), distributed over 9 days.
The day lasts on average 10 hours and 25 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 41% of the time.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 9 kph (6 mph).
The average sea temperature is of 16.5 °C (61.5 °F). Therefore, the sea is cold for swimming.

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August is generally a very mild month. The average temperature is of 16.8 °C (62 °F), with a minimum of 11.1 °C (51.9 °F) and a maximum of 22.4 °C (72.4 °F).
On the coldest nights of the month, the temperature usually drops to around 4 °C (39.5 °F). However, it dropped to -1 °C (30.2 °F) in August 1991.
On the warmest days of the month, the temperature usually reaches around 32 °C (89.5 °F). However, it reached 36 °C (96.8 °F) in August 1995.
Precipitation amounts to 115 mm (4.5 in), distributed over 9 days.
The day lasts on average 11 hours and 5 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 16 °C (61 °F). Therefore, the sea is cold for swimming.

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September is generally a warm month. The average temperature is of 18.2 °C (65 °F), with a minimum of 13 °C (55.5 °F) and a maximum of 23.3 °C (74 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 6.5 °C (44 °F). However, it dropped to 0 °C (32 °F) in September 2001.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 32 °C (89.5 °F). However, it reached 38 °C (100.4 °F) in September 1994.
Precipitation amounts to 140 mm (5.5 in), distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).
The average sea temperature is of 16.5 °C (62 °F). Therefore, the sea is cold for swimming.

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October is generally a warm month. The average temperature is of 20.8 °C (69 °F), with a minimum of 15.8 °C (60.4 °F) and a maximum of 25.8 °C (78.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 9 °C (48 °F). However, it dropped to 3 °C (37.4 °F) in October 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 33.5 °C (92.5 °F). However, it reached 39 °C (102.2 °F) in October 1991.
Precipitation amounts to 140 mm (5.5 in), distributed over 10 days.
The day lasts on average 12 hours and 55 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 18.5 °C (65.5 °F). Therefore, the sea is very cool for swimming.

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November is generally a warm to hot, muggy month. The average temperature is of 22.6 °C (73 °F), with a minimum of 17.2 °C (62.9 °F) and a maximum of 28.1 °C (82.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 11.5 °C (52.5 °F). However, it dropped to 7 °C (44.6 °F) in November 1992.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 34.5 °C (94 °F). However, it reached 38 °C (100.4 °F) in November 1991.
Precipitation amounts to 110 mm (4.3 in), distributed over 8 days.
The day lasts on average 13 hours and 40 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 73%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 20.5 °C (69 °F). Therefore, the sea is cool for swimming.

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December is generally a warm to hot, muggy month. The average temperature is of 24.9 °C (77 °F), with a minimum of 19.4 °C (66.8 °F) and a maximum of 30.5 °C (86.9 °F).
On the coldest nights of the month, the temperature usually drops to around 13.5 °C (56 °F). However, it dropped to 10 °C (50 °F) in December 1995.
On the warmest days of the month, the temperature usually reaches around 36 °C (97 °F). However, it reached 39 °C (102.2 °F) in December 1994.
Precipitation amounts to 100 mm (3.9 in), distributed over 8 days.
The day lasts on average 14 hours and 0 minutes. December 21, the summer solstice, is the longest day of the year in the Southern Hemisphere.
There are on average 7.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 22.5 °C (72.5 °F). Therefore, the sea can be considered barely acceptable for swimming.