Weather in Porto Alegre in March

A good month. March works. It is not the peak, but nothing about it fights you. Highs average 28.5 °C, lows 18.7 °C, and rain falls on 13 days — nothing in the month is working against you.

March ranks 10 of 12 — near the bottom of Porto Alegre's year. April is the month that works, and the swing between the two is 18 points, which is a different holiday rather than a slightly better one. Worth keeping in perspective: March is the weakest month of Porto Alegre's year and it is still a perfectly good one. The downside here is small.

Rain on 13 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 28.5 °C days and 18.7 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 9 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest March day reached 38.8 °C and the coldest night fell to 8.7 °C, and the wettest single day dropped 62 mm — roughly 60% of the month's rain in one day.

March is moderately variable: 26 mm in the driest year against 263 mm in the wettest, around an average of 103 mm. Roughly two Marchs in three land near that average, and the third does something else entirely.

Wind is light at 8.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 78%, high enough to notice on the warm days without dominating them.

How March sits in the year

Temperatures hold steady either side: 29.8 °C in February, 28.5 here, 25.9 in April. Nothing about the timing within the month matters much.

Daylight in March

12.3 hours of daylight, losing 0.9 hours across the month. That is between Porto Alegre's extremes of 14.1 and 10.2 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 24.9 °C in March — warm enough to stay in as long as you like. This is the warmest the water gets all year.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

March in Porto Alegre versus nearby

If Porto Alegre is one option among several, the nearby comparison is worth making. Curitiba is close enough to be a coin toss — 2.7 °C cooler, 7 days more rain. São Paulo is close enough to be a coin toss — within a degree on temperature, 7 days more rain.

So: March works, with April the better month by 10 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Porto Alegre

See all twelve months in Porto Alegre, or where else to go in March.