The 2021 Pacific Northwest (PNW) heat dome was the deadliest recorded weather event in the history of Washington State. Extreme heat events are expected to become more frequent, last longer, and become more intense in the region in the future due to climate change. Understanding barriers to and facilitators of implementing an effective heat response is critical for preparing for future extreme heat events like the PNW Heat Dome. This dataset is the product of a qualitative study conducted by the University of Washington (UW) and the Northwest Healthcare Response Network (NWHRN). The study leveraged an implementation science framework, the Updated Consolidated Framework for Implementation Research (CFIR), to identify strengths, challenges, and lessons learned related to the regional health sector’s response to the 2021 heat dome in western Washington. Data was derived from four initial hour-long regional listening sessions followed by seven targeted focus groups. Participants were emergency management contacts for health sector organizations in 15 counties in western Washington State, USA: Clallam, Grays Harbor, Island, Jefferson, King, Kitsap, Lewis, Mason, Pacific, Pierce, San Juan, Skagit, Snohomish, Thurston, and Whatcom. Listening sessions consisted of between 20 and 36 participants, for a total of 109 participants, and redacted detailed notes captured at the sessions are included in this dataset. The focus groups, which lasted between 37 to 54 minutes each, had three to six participants each (a total of 27 participants), and were arranged by organization type: 1) hospital-based clinicians, 2) local public health agencies, 3) a “miscellaneous health service” group including organizations serving older adults (“aging organizations”), a healthcare coalition, and an air ambulance provider, 4) long-term care, 5) local emergency management agencies, 6) hospital emergency management, and 7) home health, hospice, and outpatient services. De-identified transcriptions of the focus group discussions, as well as a de-identified summary matrix used for analysis are included in this dataset. The Updated CFIR informed facilitation of both listening sessions and focus groups, as well as the codebook that was used for focus group analysis. All of these instruments are included in the dataset. The UW’s Human Subjects Division determined that this research is human subjects research qualifying for exempt status (Category 2); the exemption letter is included in this dataset. This work was supported by the Wellcome Trust Grant Number 216033-Z-19-Z.