Heat Action Day: Rotterdam unites to tackle rising temperatures
Rotterdam is experiencing increasingly frequent and prolonged periods of warm weather. While summer sun can be enjoyable, for many people, temperatures above 25°C quickly become too hot. Heat is becoming an ever-greater challenge for the health, livability, and safety of the city’s residents. That’s why, on Monday 2 June 2025, we are joining forces with Rotterdams WeerWoord, the Municipality of Rotterdam, GGD Rotterdam-Rijnmond and HeatLab Rotterdam to draw attention to urban heat during the city’s first-ever Heat Action Day.
Throughout the city, the Municipality of Rotterdam and its partners will host a variety of events to raise awareness about the impact of heat. Several local organizations are contributing to the program, which includes an information market, a cooling-themed tasting event, summer walks, and performances of the play Heet hè! (“Hot, isn’t it?”) by theatre group Theaterwerkplaats voor Ouwe Rotten.
Knowledge Day: ‘Sweating Is Knowing’
On Heat Action Day, HeatLab Rotterdam will host a closed knowledge session titled Zweten is weten (“Sweating is knowing”), bringing together professionals who work with heat-related issues. The aim of the day is to share knowledge and combine efforts to better prepare the city for hot weather.
The session will be led by Lex Burdorf, professor of public health determinants at Erasmus MC, and will feature a varied program of talks and discussions. In the afternoon, participants will walk from the Timmerhuis to the Maritime Museum, where three directors from the ministries of VRS (Health, Welfare and Sport), VRO (Housing, Spatial Planning and the Environment) and IenW (Infrastructure and Water Management) will officially launch the National Heat Strategy 2025.
Rotterdam turns orange
In the evening, once temperatures begin to cool, the (now sold-out) HitteRun will begin. This urban run follows a route through shaded parts of the city. The night before Heat Action Day, on 1 June at dusk, several Rotterdam icons—including the Erasmus Bridge, Maritime Museum and Hofplein Fountain—will be lit up in orange, the global color symbolizing Heat Action Day.
Heat is also one of the central themes at the heart of the Rotterdam Rooftop Days festival, with special programming on and around the Maritime Museum.
About the HeatLab
The HeatLab Rotterdam, initiated by the Resilient Delta initiative, is a learning community focused on urban heat. Since 2024, the Convergence partners—Erasmus MC, Erasmus University Rotterdam, and TU Delft—have been working together with Rotterdam University of Applied Sciences, the Municipality of Rotterdam, and GGD Rotterdam-Rijnmond. The HeatLab brings policy, research, education, and practice together to accelerate, deepen and strengthen local knowledge exchange on heat stress across three key areas: health (gezondheid), buildings (gebouw), and neighborhoods (gebied).
Find out more about the HeatLab here.
Want to know more about Heat Action Day on 2 June? Visit the Rotterdams WeerWoord website to view the full program.