SANTIAGO, Chile (AP) — Chileans are bundling up for their coldest autumn in more than 70 years mere days after sunning in T-shirts — a dramatic change of wardrobe brought on this week by a sudden cold front gripping portions of South America unaccustomed to bitter wind chills this time of year.

Temperatures broke records along the coast of Chile and in Santiago, the capital, dipping near freezing and making this month the coldest May that the country has seen since 1950, the Chilean meteorological agency reported.

An unusual succession of polar air masses has moved over southern swaths of the continent, meteorological experts say, pushing the mercury below zero Celsius (32 Fahrenheit) in some places. It’s the latest example of extreme weather in the region — a heat wave now baking Mexico, for instance — which scientists link to climate change.