Identifying community values related to heat: Recommendations for forecast and health risk communication

Effective communication of heat risk to public audiences is critical for promoting behavioral changes that reduce susceptibility to heat-related illness. The U.S. National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) provides heat-related information to the public using social media platforms such as Facebook. We applied a novel rhetorical framework to evaluate 5 years (2015-2019) of public responses to heat-related Facebook posts from the NWS office in Phoenix (Arizona) to identify "commonplaces"or community norms, beliefs, and values that may present challenges to the effectiveness of heat risk communication. Phoenix is in one of the hottest regions in North America and is the 10th-largest metropolitan area in the U.S. We found the following two key commonplaces: (1) the normalization of heat and (2) heat as a marker of community identity. These commonplaces imply that local audiences may be resistant to behavioral change, but they can also be harnessed in an effort to promote protective action. We also found that public responses to NWS posts declined over the heat season, further suggesting the normalization of heat and highlighting the need to maintain engagement. This work provides a readily generalizable framework for other messengers of high-impact weather events to improve the effectiveness of their communication with receiver audiences.