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Summer in Rio: the city has had 33 days of Heat Levels 2 and 3 since the start of the season.
Published on 20/02/2026 - 17:18 | Updated
More than half of the season was marked by a combination of high temperatures and high levels of air humidity. Art: COR-Rio
Summer reached its 62nd day this Friday (February 20th), with the municipality of Rio de Janeiro returning to level 1 of the Extreme Heat Response Protocol (Heat 1) due to the passage of a cold front along the state's coast and the possibility of light to moderate rain until Monday (February 23rd). The change in the forecast represents a relief: more than half of the hottest season of the year has been marked, so far, by days of thermal stress – a combination of high temperatures and high levels of air humidity.
Until this Thursday (February 19th), out of a total of 61 summer days in the city, the Rio de Janeiro City Hall's Operations and Resilience Center (COR-Rio) recorded 33 days with high Heat Indices (IC) – between 36°C and 40°C. With the return to heat level 1 this Friday, the municipality also ended a sequence of eight days of thermal stress: seven at Heat Level 3 and one at Heat Level 2.
The high temperatures and humidity levels recorded in Rio since December 21st repeat a climatic pattern seen last summer. During 89 days, between December 21, 2024, and March 20, 2025, 46 days were marked by thermal stress, with the city entering Heat Level 2, Heat Level 3, and Heat Level 4.
– We experienced heat stress on more than half the days of the season, and this pattern is typical of summer in the city of Rio de Janeiro. We have high temperatures and humidity combined, generating this greater feeling of heat. These factors also contribute to the occurrence of heavy rains, which are characteristic of the season – explains Raquel Franco, chief meteorologist of the Rio Alert System, the meteorological agency of the Rio de Janeiro City Hall.
According to the Municipal Health Department (SMS), at this time of year, due to the intense heat, there is an increase in demand for care at health units. More than 13.500 people were admitted with symptoms related to the heat, such as sunstroke, dehydration, respiratory problems, and variations in blood pressure. For the Superintendent of Health Surveillance, Gislani Mateus, monitoring the indicators and communicating with the population are fundamental in the care against heat stress:
– The Epidemiological Intelligence Center (CIE) of the Municipal Health Department monitors health indicators integrated with climate in real time, which is fundamental to guaranteeing the protection of Rio de Janeiro residents during the summer. Extreme heat demands a great effort from the body to regulate temperature, and we soon see the reflection of this in medical care. By closely monitoring this data, we can direct care and issue the correct alerts, especially to protect at-risk groups and chronic patients, who are the first to suffer the severe impacts of heat stress – analyzes Gislani.
The city of Rio has not recorded a heat index of 4 for a year.
Exactly one year ago, on February 20, 2025, the municipality of Rio de Janeiro ended a four-day streak at level 4 of the Extreme Heat Response Protocol. It was the first time the city had reached the most critical heat level since June 2024, when the pioneering climate resilience public policy in Brazil was implemented by the Rio de Janeiro City Hall.
Since then, the city has not again met the criteria for a change to Heat Level 4. This climatic condition is characterized by very high heat indices (40°C to 44°C), with a forecast of persistence or increase for at least three consecutive days. At this level, COR-Rio advises the population to adapt their routines in order to protect citizens from the impacts of heat waves.
Among the actions taken during the Heat Wave 4 are the designation of existing public facilities with air conditioning or refrigeration to serve as cooling points; in addition to guidance on adequate cooling or shading. The availability of hydration stations or water distribution points in areas serving the most vulnerable populations may also be expanded.
At heat level 4, there is still the possibility of canceling or rescheduling medium and large-scale events, mega-events in outdoor areas, if they do not adapt. At this level, there may also be the suspension of activities carried out in outdoor areas and their transfer to shaded or indoor spaces.
During the "Heat Level 4" phase, the public can find the addresses of cooling and hydration points throughout the city on the COR.Rio app (free download for Android and iOS) and on the Operations and Resilience Center website (cor.rio).
All actions are guided by the Committee for the Development of Protocols to Address Extreme Heat and approved by the mayor of Rio. Updates regarding heat levels are made available to citizens on the social media channels of the Municipal Health Department and COR-Rio (@operacoesrio).
Rio's initiative against extreme heat is internationally recognized.
The Protocol to Address Extreme Heat, launched by the Rio de Janeiro City Hall as a strategic response to the increase in heat waves and their impacts on public health, was one of the winning initiatives of the Local Leaders Awards 2025, a Bloomberg Philanthropies award that recognizes effective and innovative local policies to address climate change. The achievement was announced during the Local Leaders Forum at COP30, held in November 2025 in Rio de Janeiro.
The city won the award in the category "Safer Infrastructure for a Changing World." The initiative is coordinated by the Rio de Janeiro City Hall's Center for Operations and Resilience (COR-Rio), along with the Health (SMS) and Environment and Climate (SMAC) secretariats.
