Marathons in South America: dates, weather and how to choose

South America’s marathon calendar runs the other way round from Europe and North America: most big races fall between April and September, in the southern autumn and winter, when the cities of Argentina, Chile, Uruguay and southern Brazil are at their coolest. Below are the road marathons we list on the continent, in calendar order, with how you get in and the figures that matter most when choosing one.

“Climb” is the total elevation gain of the course. “Usual start temp.” is the average temperature at the start time over the last 10 years on race day. Dates marked “est.” follow the race’s usual slot and are not yet confirmed.

How to choose between them

Go south and go in winter for cool weather

Latitude decides most of it. Races in the far south, like Rosario in June or Buenos Aires and Punta del Este in September, usually start around 8 to 12°C. Closer to the equator, in Caracas, Cali or Rio, it stays warm all year and starts are often in the high teens or above, which is why many of these races start at dawn.

Flat and fast

For a personal best, look at the flat courses in the cool months: Buenos Aires, Rosario, Porto Alegre and Florianópolis all climb very little. Compare them with the rest of the world in the best marathons for a PB.

Altitude

A few races are run high in the Andes. La Paz sits well above 3,500 m and Medellín close to 1,500 m. At that height the air holds less oxygen, so expect to run slower than at sea level and arrive a few days early if you can.

Entry

Almost every race here is first-come, first-served, and most international runners can sign up online. The entry column shows the exceptions; check each race’s page for when registration opens.

Trail marathons

The continent also has some of the most spectacular trail races in the world, in Patagonia: the Patagonian International Marathon in Torres del Paine and the Patagonia Run 42K near San Martín de los Andes. Expect serious climbing and cold starts.

Compare any of these side by side, or filter by month, climb and temperature in the race finder. For races further north, see spring marathons in the USA and Canada.