A new weather replay application now allows users to explore global weather events dating back to 1940 through interactive climate and historical visualisation tools.
The Copernicus Climate Change Service has launched a new digital application designed to help users explore historical weather conditions and major climate events dating back more than eight decades.
Called Weather Replay, the platform allows users to revisit weather conditions anywhere in the world, hour by hour, from January 1940 up to just a few days before the present.
Developed using the ERA5 reanalysis dataset and infrastructure from the European Centre for Medium-Range Weather Forecasts (ECMWF), the application functions as a global weather “time machine”, enabling users to visualise how major weather events unfolded over time.
The tool includes curated historical events such as Hurricane Katrina, Cyclone Nargis in Myanmar and the 2003 European heatwave, while also allowing users to search any location or date globally to explore historical weather conditions.
According to the Copernicus Climate Change Service, the initiative forms part of a broader effort to make climate and weather data more accessible to the public, media organisations, researchers and educators.
The application combines historical reanalysis datasets with near-real-time updates, making it useful for climate explainers, historical comparisons, anniversary reporting, data-driven storytelling and contextual reporting around extreme weather events.
Users can access multiple weather variables, including temperature, precipitation, wind and wind gusts, atmospheric pressure, jet stream patterns and upper-air atmospheric conditions.
Climate scientists say tools such as Weather Replay can help strengthen public understanding of climate systems and improve accessibility to scientific data by transforming complex datasets into visual, interactive experiences.
The launch comes as demand continues growing globally for more accessible climate information and digital tools capable of helping both journalists and the public better understand the increasing impact of extreme weather and climate change.
The Weather Replay platform is freely accessible online as part of the broader Copernicus climate and environmental monitoring ecosystem.
