Climate Shift Index AlertFebruary 20, 2025

Climate change fuels record February heat in Brazil ahead of Carnival

More than 127 million people across Brazil are experiencing heat made at least five times more likely because of climate change from February 14-20. The heat has prompted authorities to issue excessive heat alerts as the nation prepares for Carnival, a week-long festival and the most popular holiday in Brazil.  

Cities are ramping up hydration stations and public health services to address rising cases of dehydration, heat exhaustion, and heat stroke cases. Meanwhile, water shortages and limited access to air conditioning are disrupting daily life.

CSI Alert Brazil 2025

How has climate change influenced this heat?

Impacts:

City

Date of Highest Temperature


Highest Temperature (°C)

Days Above CSI 3 (Tavg)


Days Above CSI 5 (Tavg) 

Number of Days with Temperature Max Above 30°C 

Foz do Iguaçu

February 18, 2025

38.8

5

2

7

São Gonçalo

February 18, 2025

37.5

2

0

7

Petrolina

February 20, 2025

37.0

4

3

7

Praia Grande

February 17, 2025

36.7

1

1

5

São Vicente

February 17, 2025

36.7

1

1

5

Campos dos Goytacazes

February 18, 2025

36.5

5

2

7

Governador Valadares

February 18, 2025

36.4

5

1

7

Volta Redonda

February 18, 2025

36.1

5

5

7

Bauru

February 20, 2025

35.4

6

5

7

Joinville

February 17, 2025

34.8

2

1

3

Cuiabá

February 20, 2025

34.7

4

2

5

Várzea Grande

February 20, 2025

34.7

3

2

5

Cariacica

February 17, 2025

34.5

6

5

7

Petrópolis

February 18, 2025

34.4

4

1

6

Piracicaba

February 17, 2025

34.4

6

5

7

Ribeirão Preto

February 17, 2025

34.3

6

5

7

What do experts say?

Dr. Kristina Dahl, VP for Science at Climate Central, said: 

“This exceptional heat in Brazil would be essentially impossible without the influence of climate change,” said Dr. Kristina Dahl.  ”As global temperatures continue to rise due to fossil fuel emissions, we can expect more heat waves to coincide with major cultural events like Carnival and sports events like the Rio Open.”

To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.org

How do we know climate change is influencing this heat?

The Climate Shift Index uses peer-reviewed methodology and real-time data to estimate how climate change has increased the likelihood of a particular daily temperature.

We compare the likelihood that these temperatures would occur in a world without carbon emissions released by humans, versus in today’s world with decades of carbon emissions building up in the atmosphere. This is an established scientific method to determine how much climate change has or has not affected individual extreme weather events.