This bill, titled the "Smoke and Heat Ready Communities Act of 2025," amends the Clean Air Act to establish a new grant program. Administered by the Environmental Protection Agency (EPA), this program will provide grants to air pollution control agencies to help local communities detect, prepare for, communicate about, and mitigate the environmental and public health impacts of wildfire smoke and extreme heat. Eligible activities include monitoring air quality, conducting community outreach, deploying air quality equipment, equipping public buildings with air filtration, and distributing protective gear like masks and portable air purifiers. The legislation also directs the EPA Administrator to establish four Centers of Excellence for Wildfire Smoke and Extreme Heat at institutions of higher education. These centers will conduct research on the public health effects of smoke and heat, and develop strategies for communities to better respond to these events. Additionally, the EPA is mandated to carry out broader research on health effects, interventions, and improved monitoring and prediction tools for wildfire smoke and extreme heat. Furthermore, the bill creates a competitive grant program to assist States, local governments, Indian Tribes, and Native Hawaiian organizations in developing and implementing collaborative community plans to mitigate the impacts of smoke emissions and extreme heat. Applicants for these grants must collaborate with public higher education or research institutions that possess relevant expertise. The bill authorizes appropriations for all these programs to ensure their implementation.