Abstract Oceans absorb most anthropogenic heat and a large share of carbon emissions, driving sea surface temperature (SST) increases and intensifying marine heatwaves (MHWs). Although rising MHW frequency is well documented, most studies rely on the standard fixed‑baseline approach (Hobday et al., 2016), which uses a static climatology and is sensitive to long‑term warming, thereby amplifying recent extremes and raising concerns about future MHW “saturation” (Rosselló et al., 2023). To address these issues, we compare three detection frameworks—fixed baseline (1982–2011), 20‑year moving baseline (Rosselló et al., 2023), and a detrended method that removes the linear warming trend (Martínez et al., 2023)—across the Mediterranean Sea, a rapidly warming and ecologically vulnerable basin. Using SST data for 1982–2024, all three methods identify 2024 as the peak MHW year of the past two decades, with fixed and moving baselines also registering the longest‑lasting events. Regionally, the eastern Mediterranean, where warming is strongest, recorded the most MHW days in 2024, whereas the western basin experienced exceptionally intense events in 2022. Depending on the detection framework, estimated MHW exposure across the Mediterranean can vary by up to fourfold. Fixed baselines remain useful for assessing thermal stress relative to historical conditions, while moving and detrended methods better track anomalies in a changing climate. Aligning detection frameworks with research and policy goals is therefore crucial for reliable climate risk assessment and regional adaptation planning. The research of this talk has been published on Ocean Science https://os.copernicus.org/articles/21/1987/2025/ Our speaker Blanca Fernández‑Álvarez is a researcher at the IMEDEA CSIC and works with Ananda Pascual. What is a Climate Coffee? #climatecoffees are short (circa 40 min: 20 min talk + 20 min Q&A), relaxed meetings for scientists to share ideas, discuss methods, and communicate new results. They are open to speakers of all seniority; we especially encourage early-career scientists to become speakers. The Coffees are an exciting opportunity for scientists to build a network and disseminate recent results peer-to-peer. We invite researchers from across the climate science community to join us for this series of regular online knowledge exchange events. Video of the talk: https://www.youtube.com/watch?v=3jVrQQ0D9y4&list=PLvVwf0FRZw4oQyHw-6TMm0u2FjFGvnvx6&index=1 Organisation The Climate Coffees are organized by the Horizon Europe projects ObsSea4Clim, OCEAN ICE, the National Center for Climate Research - DMI Danish Meteorological Institute and the European Climate Research Alliance. Sign up for the next climate coffees: https://www.eventbrite.com/cc/climate-coffees-series-talks-on-and-about-climate-2655309 Disclaimer Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them.