Data Points

A global challenge: Killer Heat On the Horizon

(Photo courtesy of Union of Concerned Scientists)

Deadly heat will threaten most Bay Area residents in the late 21st century without global action to fight climate change. 

All residents except those in San Francisco will face days each year from 2070 to 2099 when the temperature is expected to rise above 105 degrees Fahrenheit, according to the report “Killer Heat in the United States: Climate Choices and the Future of Dangerously Hot Days.” The report was released July 16 by the Union of Concerned Scientists. 

Yes, late century is 2070 to 2099. 

Here’s how the counties rank by number of days each year from 2070 to 2099 when the temperature is expected to be above 105 degrees.

1
1. Solano County — 25
2
2. Napa County — 17
3
3. Contra Costa County — 14
4
4. Alameda County — 6
5
5. Santa Clara County — 6
6
6. Sonoma County — 5
7
7. San Mateo County — 2
8
8. Marin County — 2
9
9. San Francisco — 0
1. Solano County — 25
2. Napa County — 17
3. Contra Costa County — 14
4. Alameda County — 6
5. Santa Clara County — 6
6. Sonoma County — 5
7. San Mateo County — 2
8. Marin County — 2
9. San Francisco — 0

The historical trend for each Bay Area county during the last 30 years of the 20th century was zero days of heat above 105 degrees. 

“There are big changes on the horizon for many counties in the Bay Area,” said Kristina Dahl, the study’s lead author. 

Source: Union of Concerned Scientists