Weather in Curitiba in September

A good month. September works. It is not the peak, but nothing about it fights you. Highs average 22.9 °C, lows 11.5 °C, and rain falls on 13 days — nothing in the month is working against you.

September ranks 5 of 12 in Curitiba: past the worst of the year but short of August, which is the month to book if the dates are open.

Rain on 13 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest September day reached 33.3 °C and the coldest night fell to -2.2 °C, and the wettest single day dropped 50 mm — roughly 41% of the month's rain in one day.

September is moderately variable: 38 mm in the driest year against 349 mm in the wettest, around an average of 122 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 3.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 81%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 21.1 °C in August, 22.9 here, 24.4 in October. Nothing about the timing within the month matters much. Rain is the thing that moves: October brings 5 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in September

11.9 hours of daylight, gaining 0.7 hours across the month. That is between Curitiba's extremes of 13.7 and 10.6 hours, so days are long enough not to constrain the plan.

An inland climate

Despite being inland, the year stays fairly even: 17.3 °C between the year's warmest afternoons and coldest nights. At 924 m the air is thin enough to matter — sun that burns faster than the temperature suggests, and nights that cool off quickly.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself.

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

September in Curitiba versus nearby

If Curitiba is one option among several, the nearby comparison is worth making. São Paulo is close enough to be a coin toss — 4.1 °C warmer, 3 days less rain. Porto Alegre is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: September works, with August the better month by 9 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Curitiba

See all twelve months in Curitiba, or where else to go in September.