A collaborative project between the City of Vancouver, Vancouver Coastal Health, and the BC Centre for Disease Control.

City of Vancouver and Vancouver Coastal Health conducted a self-reported survey of indoor temperatures during the summer of 2021. This survey was sent out via Twitter and Easy Survey platforms on July 29 asking participants to self-report the highest indoor air temperature that was recalled during the first and very dangerous heat event of the summer (June 25-July 1) often referred to as the “heat dome”. Respondents were also asked to record more detailed information throughout the day on indoor temperatures for the subsequent less severe heat events (July 29-August 2, August 11-15) that summer. This survey also included questions on characteristics of the respondent’s residence and actions taken to reduce heat. A summary of the responses follows:

Distribution of highest reported indoor air temperature during the June 25-July 1 heat event

One hundred and fifty respondents reported the highest indoor air temperature recorded in their home during the heat event from June 25-July 1, referred to as the “heat dome” (Fig. 1). The mean highest indoor air temperature reported was 34.1°C, the median 33°C, while the highest indoor air temperature reported by any participant was 56.2°C (a substantial outlier, with the second-highest reported maximum temperature being 47°C). During this time period, the highest outdoor air temperature recorded at Vancouver Harbour was on June 28 at 33.8°C.