A mass of polar air advancing from the south is causing a sharp drop in temperatures across south-eastern South America. In Brazil, the national meteorological service Climatempo warns of frost in Rio Grande do Sul and Santa Catarina, with minimums between -3°C and -6°C in some areas. The cold front is also reaching São Paulo, where the maximum will struggle to reach 17°C, and Rio de Janeiro, where rain is forecast. The cold snap is expected to ease gradually from Sunday, though frost may linger in high-altitude areas.

In Argentina, the national weather service has issued alerts for a storm system that will bring heavy rain, hail, and strong winds to Buenos Aires province and other areas from Sunday night, lasting 48 hours. Before that, Saturday will be cold and dry, with temperatures around 3°C in the capital. Paraguay is also experiencing unusually low temperatures for July, with Asunción seeing a maximum of just 16°C and Encarnación dropping to 4°C. No precipitation is expected there, but the cold air is a marked departure from seasonal norms.

Further north, a different pattern prevails. In Venezuela, cities like Maracaibo and Ciudad Guayana are seeing temperatures above 30°C with intermittent showers, while in Peru, the Amazonian city of Iquitos is receiving moderate to heavy rain. Colombia’s Ideam institute forecasts widespread rainfall over the weekend, with tropical wave number 22 arriving on Sunday to intensify precipitation in the Caribbean, Andean, and Pacific regions. Mexico is also experiencing a mix of heat and storms: the national meteorological service (SMN) predicts heavy rain in Jalisco and Michoacán, with possible hail, while Mexico City faces a 90% chance of rain and authorities have issued a red alert for the Cuajimalpa borough due to intense rainfall and risk of landslides.

Across the Atlantic, Spain’s AEMET agency reports a contrasting picture: stable, hot weather with temperatures reaching 42°C in Andalusia and 38°C in Madrid, as a high-pressure system dominates the Iberian Peninsula. The juxtaposition of a cold southern cone and a scorching Europe underscores the variability of weather patterns in early July. Looking ahead, forecasters in Brazil expect the cold to moderate by Monday, while Argentina’s storm system will clear by Tuesday, and Mexico’s rainy season will continue with the passage of tropical wave 15. The next milestone to watch is the arrival of tropical wave 22 in Colombia on Sunday, which could bring further flooding risks.