Extreme heat risks to pregnancy driven by climate change: South America

2020 to 2024

We counted the number of days with temperatures warmer than 95% of temperatures observed at a given location (also referred to as temperatures above the 95th percentile) — a threshold which research1 shows can bring increased risk of preterm birth. We define these extremely hot days as “pregnancy heat-risk days.”

  • During 2020 to 2024, nearly all of the analyzed countries in South America (12 out of 14) experienced at least two additional weeks’ worth of pregnancy heat-risk days on average each year due to climate change.

  • Eight of these countries experienced at one additional months’ worth of pregnancy heat-risk days each year on average, including Peru (42), Guyana (36), and Ecuador (35).

  • In nearly all South American countries (12 out of 14), climate change at least doubled the average annual number of pregnancy heat-risk days, compared to a world without climate change.

Explore data for countries and cities across South America in the interactive maps below.


Countries with the most pregnancy heat-risk days added by climate change




Cities with the most pregnancy heat-risk days added by climate change



1We chose this percentile based on peer-reviewed research from Kuehn et al. (2017), Wang et al. (2013), Wang et al. (2024), and McElroy et al. (2022).