A resident of San Francisco, California, would feel very much at home with regard to the summer weather in Cape Town, South Africa. South Africa being in the southern hemisphere, of course, it’s seasons are the reverse of those in the northern hemisphere, so summer in San Francisco is winter in Cape Town, and vice versa. Both are coastal cities with mild summers, characterized by cool breezes. San Francisco can feel very cool during the summer due to the unique geographic characteristics of the bay area, which can make certain parts extremely windy. In fact, baseball in San Francisco has been notoriously complicated due to the severe wind patterns that develop within the confines of the stadium where the Major League Baseball Giants play, with miniature tornados a common occurrence.
As with summer, winters in the two cities are very similar, although San Francisco is generally cooler, as Cape Town’s location at the merging of the Indian and Atlantic Oceans generates unique weather patterns and provides a more consistently warm climate during its winter than is the case in northern California. Global climate change is making more likely incidences of snowfall in both cities than historically has been the case. Cape Town is much more of a “beach” town than San Francisco, as California’s main beach activity occurs further south from Monterrey to Pismo to Santa Barbara to Los Angeles and San Diego.
A family traveling from San Francisco to Cape Town would basically pack as though it was going to a location with the same climate as its own. The main difference would be cultural, with the latter, as noted, more of a vacation area where beach activity is the norm.