A severe heat wave is expected to affect the western United States this weekend. The heat wave will bring extremely high temperatures to the region, with dozens of record highs predicted to fall in at least 12 states. High temperatures are forecast to be significantly hotter than usual, even for the peak of summer.

The heat wave is expected to affect tens of millions of people from California to Canada, with around 40 million under heat alerts. Further details about the heat wave, including its potential impact and what a heat dome is, are available from KXXV News.