Heat waves likely to become longer, more intense — even in Bay Area, study shows

Summers in San Francisco may soon feel more like the warmer East Bay. The East Bay may soon feel more like Sacramento. And Sacramento — well, it might just be too hot to stick around any longer.

One of the most detailed studies on rising temperatures suggests that few places in the United States will be unaffected by extreme heat by the middle of this century. Without significant steps to curb global warming, most of the nation will see more than twice as many days when the heat index, or “feels like” temperature, exceeds 100 degrees, according to the study released Tuesday by the Union of Concerned Scientists. Many spots will see several more days.

Even places with relatively moderate climates, such as the Bay Area, will begin to experience uncomfortable and even dangerous spikes in temperatures, the study concludes. Livermore will go from averaging one day a year with a heat index above 100 degrees to seven days by 2050. Napa will go from averaging no 100-degree days to six during this period. And Morgan Hill will jump from zero to five.

Read the entire article at SFChronicle.com