Those of us fortunate enough to routinely cross the Golden Gate Bridge, one of the great bridges of the world, know what to expect in the summer. Fog often whips through the suspension cables. Tourists are bundled up in new souvenir sweatshirts. It can feel like being in a localized storm. I love it.
On the bridge on a foggy day, even in the middle of a summer heat wave elsewhere in California, the thermometer in my car, measuring the cold air rushing off the Pacific, will usually read 59 degrees. As I drive home, that temperature gauge ticks up, steady as the odometer. Where I live, 20 miles north of the bridge, it could be 100 degrees — a 40-degree range in about 15 minutes.
Fog is more than just a surreal quirk of San Francisco and the surrounding Bay Area. It is a vital part of its climatology and culture. It is a life force — and one with an uncertain future.