September weather forecast
Porto Alegre, Brazil

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Weather in September

September in Porto Alegre marks a noticeable change with temperatures up at 22°C (71.6°F) and rainfall down to 66mm (2.6"). The city embraces spring with warmer weather and longer daylight hours. Porto Alegre in September offers a perfect blend of mild climate, extended sunlight, and reduced rainfall. Despite a higher cloud coverage, September is perfect for indulging in outdoor activities and exploring the city's famed food scene. The slightly cooler sea temperature brings a different kind of joy to beach visits.

Temperature

September's onset in Porto Alegre records an average high-temperature of a still agreeable 22°C (71.6°F), a near match to August's 21.1°C (70°F). The average temperature in Porto Alegre during September nights dips to a mild 13.1°C (55.6°F).

Humidity

In Porto Alegre, the average relative humidity in September is 80%.

Rainfall

In September, the rain falls for 13.9 days. Throughout September, 66mm (2.6") of precipitation is accumulated. In Porto Alegre, during the entire year, the rain falls for 148.3 days and collects up to 805mm (31.69") of precipitation.

Sea temperature

In Porto Alegre, the average seawater temperature in September is 16.3°C (61.3°F).
Note: Most people do not enjoy swimming in water that is 16.3°C (61.3°F). Breathing becomes increasingly challenging as the water temperature dips under 21°C (69.8°F).

Daylight

The average length of the day in September is 11h and 56min.
On the first day of the month, sunrise is at 06:39 and sunset at 18:10. On the last day of September, in Porto Alegre, sunrise is at 06:03 and sunset at 18:25 -03.

Sunshine

The month with the least sunshine is September, with an average of 7h of sunshine.

UV index

In Porto Alegre, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The daily maximum UV index of 5 in September interprets into the following advice:
Make use of precautions - Suggestions to resist sunburn are communicated. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

Frequently asked questions

What is the average September temperature in Porto Alegre?

The average high-temperature and low-temperature in Porto Alegre, Brazil, during September are 22°C (71.6°F) and 13.1°C (55.6°F) respectively. The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, in March is calculated to be 31°C (87.8°F).

What is the average humidity in September in Porto Alegre?

The average relative humidity in September in Porto Alegre, Brazil, is 80%.

How much does it rain in Porto Alegre in September?

In Porto Alegre, in September, it is raining for 13.9 days, with typically 66mm (2.6") of accumulated precipitation.

How cold is the water in September in Porto Alegre?

In Porto Alegre, the average seawater temperature in September is 16.3°C (61.3°F). Swimming in 16.3°C (61.3°F) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 21°C (69.8°F).

What is the average length of the day in September in Porto Alegre?

In September, the average day length is 11h and 56min.

What time are sunrise and sunset in September in Porto Alegre?

On the first day of September in Porto Alegre, sunrise is at 06:39 and sunset at 18:10. On the last day of the month, sunrise is at 06:03 and sunset at 18:25 -03.

What is the month with the least sunshine in Porto Alegre?

September has the least sunshine of the year in Porto Alegre, Brazil, with an average of 7h of sunshine.

How many hours of sunshine does Porto Alegre have in September?

In September, the average sunshine duration in Porto Alegre is 7h.

What is the UV index intensity in September in Porto Alegre?

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from unprotected exposure to UV radiation.

Average temperature in September
Porto Alegre, Brazil

Average temperature in September - Porto Alegre, Brazil
  • Average high temperature in September: 22°C

The warmest month (with the highest average high temperature) is February (30.5°C).
The month with the lowest average high temperature is July (18.8°C).

  • Average low temperature in September: 13.1°C

The months with the highest average low temperature are January and February (20°C).
The coldest month (with the lowest average low temperature) is July (10.6°C).

Average pressure in September
Porto Alegre, Brazil

Average pressure in September - Porto Alegre, Brazil
  • Average pressure in September: 1017.2mbar

The month with the highest atmospheric pressure is July (1019.8mbar).
The month with the lowest atmospheric pressure is December (1011.4mbar).

Average wind speed in September
Porto Alegre, Brazil

Average wind speed in September - Porto Alegre, Brazil
  • Average wind speed in September: 12km/h

The windiest month (with the highest average wind speed) is October (12.1km/h).
The calmest month (with the lowest average wind speed) is May (10km/h).

Average humidity in September
Porto Alegre, Brazil

Average humidity in September - Porto Alegre, Brazil
  • Average humidity in September: 80%

The month with the highest relative humidity is June (81%).
The month with the lowest relative humidity is December (71%).

Average rainfall in September
Porto Alegre, Brazil

Average rainfall in September - Porto Alegre, Brazil
  • Average rainfall in September: 66mm

The wettest month (with the highest rainfall) is July (103mm).
The driest month (with the least rainfall) is April (36mm).

Average rainfall days in September
Porto Alegre, Brazil

Average rainfall days in September - Porto Alegre, Brazil
  • Average rainfall days in September: 13.9 days

The month with the highest number of rainy days is October (15 days).
The month with the least rainy days is April (9.8 days).

Average sea temperature in September
Porto Alegre, Brazil

Average sea temperature in September - Porto Alegre, Brazil
  • Average sea temperature in September: 16.3°C

The best month for swimming (with the highest average sea temperature) is January (24.7°C).
The coldest month (with the lowest average sea temperature) is August (15.8°C).

Average daylight in September /
Average sunshine in September
Porto Alegre, Brazil

Average daylight in September / Average sunshine in September - Porto Alegre, Brazil
  • Average daylight in September: 11h and 5min

The month with the longest days is December (Average daylight: 14h and 0min).
The month with the shortest days is June (Average daylight: 10h and 12min).

  • Average sunshine in September: 7h and 0min

The month with the most sunshine is December (Average sunshine: 8h and 18min).
The month with the least sunshine is September (Average sunshine: 7h and 0min).

Average sunshine days in September
Porto Alegre, Brazil

Average sunshine days in September - Porto Alegre, Brazil
  • Average sunshine days in September: 14.4 days

The month with the most sunshine days is May (19.9 days).
The month with the least sunshine days is September (14.4 days).

Average UV index in September
Porto Alegre, Brazil

Average UV index in September - Porto Alegre, Brazil
  • Average UV index in September: 5

The month with the highest UV index is December (UV index 7).
The months with the lowest UV index are May, June and July (UV index 4).

Average cloud cover in September
Porto Alegre, Brazil

Average cloud cover in September - Porto Alegre, Brazil
  • Average cloud cover in September: 41

The month with the most cloud cover is September (Cloud cover 41).
The month with the least cloud cover is November (Cloud cover 32).

Average visibility in September
Porto Alegre, Brazil

Average visibility in September - Porto Alegre, Brazil
  • Average visibility in September: 9km

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).

Porto Alegre, Brazil

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