California’s rainy season is ending, and it has been especially dry in the populous southern part of the state. Since last July, Los Angeles should have had about 15 inches of rain. Instead, it has had a little more than 3. Even in a normal year, Southern California’s climate spawns wildfires. Barely a drop of rain falls during the summer, so the region turns into a big brown pyre. In the autumn come the warm, dry Santa Ana winds that fan minor fires into major ones. This year, the fire season will be somewhere between merely bad and truly catastrophic. In the latter case, think of Katrina with flames in place of floodwaters.