Climate-driven electricity-hydrogen networking accelerates cost competitive carbon neutrality in Chinese cities

City-level policies oriented toward carbon neutrality are accelerating the deep integration of hydrogen into urban energy systems. Here we develop a climate-driven electricity-hydrogen network expansion analytical model, driven by 10-year 87600-hour city-level climate data from typical Chinese cities, to evaluate the coordinated development of electricity and hydrogen infrastructure. Our results suggest that the coordinated expansion of these networks could reduce accumulated system costs by 17.28 billion American dollars (6.37%) and lower annual carbon emissions by 49.33 million tonnes (96.37%) by 2060. Deploying 2037 kilometers of hydrogen pipelines could avoid excessive investment in 21.89 gigawatts (25.42%) of hydrogen storage capacity. To support broader climate policies, we identify localized, staged pathways for renewable energy development and fossil-fuel plant retirements. Moreover, our analysis indicates that utilizing prudent carbon pricing, rather than strict carbon limits, plays a critical role in driving decarbonization while safeguarding energy security. Coordinated electricity and hydrogen network expansion lowers costs and emissions while enabling efficient hydrogen transport, identified using a climate-driven city-level modelling framework based on long-term hourly data across Chinese cities.