Porto Alegre is warmest in February, averaging 31° by day and 20° at night. The wettest month is September with 198 mm, and the year brings about 1372 mm in total.
Month by month
| Month | High | Low | Rain | Sea | Daylight | Good for |
|---|---|---|---|---|---|---|
| January | 31° | 20° | 109 mm | 25° | 13.7 h | Mild |
| February | 31° | 20° | 59 mm | 26° | 13.1 h | Beach weather |
| March | 30° | 18° | 78 mm | 25° | 12.2 h | Beach weather |
| April | 27° | 16° | 96 mm | 23° | 11.3 h | Beach weather |
| May | 22° | 13° | 186 mm | 19° | 10.5 h | Rainy season |
| June | 20° | 10° | 165 mm | 16° | 10.1 h | Mild |
| July | 19° | 9° | 130 mm | 14° | 10.2 h | Mild |
| August | 21° | 11° | 84 mm | 15° | 10.9 h | Sightseeing |
| September | 23° | 13° | 198 mm | 17° | 11.8 h | Rainy season |
| October | 24° | 15° | 84 mm | 20° | 12.7 h | Sightseeing |
| November | 26° | 16° | 102 mm | 22° | 13.5 h | Beach weather |
| December | 29° | 18° | 81 mm | 24° | 13.9 h | Beach weather |
High and low are average daily maximum and minimum, rain is typical monthly total, sea is the average surface temperature, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER and NOAA MUR — averages, not promises.
When to go
Beach weather: February, March, April, November and December — highs around 29°, nights no colder than 16°, and at most 102 mm of rain in a month. The sea sits at 22–26° then.
Walking the city: August and October — highs of 21–24° and no more than 84 mm of rain a month.
Wet season: May and September — up to 198 mm in a single month.