Dangerous heat in the West driven by climate change

Dangerous heat will impact the Western U.S. between July 8-11. Human-caused climate change will make this extreme heat at least three times more likely for around 43 million people and five times more likely for more than 25 million people. 

Unusual temperatures: Temperatures will reach up to 90-103°F (32-39°C) in Colorado, Utah, northwest New Mexico, and east Arizona. These temperatures will be 8-12°F (4-7°C) above what is normal for this time of the year. Some even hotter temperatures above 110°F (43°C) are forecast in the deserts of southwest Arizona and southern California during this time, which is more than 5°F (3°C) hotter than normal for this time of year.

Climate influence: Daily average temperatures will reach a CSI level of 5 in cities across multiple states across the Western U.S., including Phoenix, Santa Fe, Fresno, Las Vegas, and Denver. A CSI 5 indicates that human-caused climate change made this event at least 5 times more likely, signaling a significant climate change event.